1 title "PIC16F870 Unilink(R) Interface by Werner Johansson (c) 2002-2003"
\r
2 subtitl "Definitions"
\r
3 list c=150,P=16F870,R=DEC,F=inhx8m
\r
4 include "p16f870.inc" ; Standard equates & Macros
\r
5 ERRORLEVEL 1,-302 ; Get rid of those annoying 302 msgs!
\r
8 ;----------------------------------------------------------------
\r
9 ; The Configuration Word
\r
10 __CONFIG _HS_OSC&_WDT_OFF&_PWRTE_ON&_BODEN_ON&_LVP_OFF&_CPD_OFF&_WRT_ENABLE_ON&_DEBUG_OFF&_CP_OFF
\r
12 ;----------------------------------------------------------------
\r
14 ;----------------------------------------------------------------
\r
15 ; Fix the DelayW routine so it actually delays W/10 ms...
\r
16 ; No checksum checking is done on incoming packets
\r
17 ; Investigate whether I actually have to save PCLATH in ISH, maybe save FSR?
\r
18 ; Move RS232 code into ISH
\r
19 ; Check Overrun errors from the UART
\r
20 ; Implement lots of other Unilink commands (Text display, time display etc.)
\r
21 ; Implement the Watchdog Timer (might be useful even though I haven't seen it hang yet..)
\r
23 ;----------------------------------------------------------------
\r
25 ;----------------------------------------------------------------
\r
28 ; 0.5 Issues slave breaks seemingly without hickups (!)
\r
29 ; 0.4 Some fixups in the bootstrap code (I actually had to put the PIC in my PICSTART Plus programmer again :))
\r
30 ; 0.3 Implementing more Unilink commands and RingIndicator control (to wake the computer from sleep)
\r
31 ; 0.2 First attempt at responding to the Anyone command
\r
32 ; 0.1 Receives Unilink data OK, relays it to serial
\r
33 ; 0.0 Very first "F**king No Work!" version
\r
35 ;----------------------------------------------------------------
\r
37 ;----------------------------------------------------------------
\r
38 ; Unilink BUSON IN (blue) connected to RC2/CCP1
\r
39 ; Unilink DATA (green) connected to RC3
\r
40 ; Unilink BUSON OUT (blue) connected to RC4 (this is for daisy-chaining)
\r
41 ; Unilink CLK (yellow) connected to RB0/INT (Interrupt pin)
\r
42 ; Unilink RST (lilac) connected to RA4
\r
43 ; LCD RS connected to pin RB1 (The LCD is a standard 16x1 char HD44780 compatible unit)
\r
44 ; LCD RW connected to pin RB2
\r
45 ; LCD E connected to pin RB3
\r
46 ; LCD DB4-DB7 connected to RB4-RB7
\r
47 ; RS-232 TX from computer connected to RC7/RX
\r
48 ; RS-232 RX to computer connected to RC6/TX
\r
49 ; RS-232 RI to computer connected to RC5
\r
51 ; This leaves RC0, RC1 and the analog inputs (AN0-AN4) free for now...
\r
53 #define BUSON_IN_BIT PORTC,2
\r
54 #define DATA_BIT PORTC,3
\r
55 #define BUSON_OUT_BIT PORTC,4
\r
56 #define CLK_BIT PORTB,0
\r
57 #define RST_BIT PORTA,4
\r
59 #define LCD_RS_BIT PORTB,1
\r
60 #define LCD_RW_BIT PORTB,2
\r
61 #define LCD_E_BIT PORTB,3
\r
62 #define LCD_DB4_BIT PORTB,4
\r
63 #define LCD_DB5_BIT PORTB,5
\r
64 #define LCD_DB6_BIT PORTB,6
\r
65 #define LCD_DB7_BIT PORTB,7
\r
67 #define RS232_RI_BIT PORTC,5
\r
69 ;----------------------------------------------------------------
\r
70 ; FILE REGISTER USAGE
\r
71 ;----------------------------------------------------------------
\r
72 TrackName00 equ 20h ; Buffer for TrackName
\r
100 TrackName1c equ 3ch
\r
101 TrackName1d equ 3dh
\r
102 TrackName1e equ 3eh
\r
103 TrackName1f equ 3fh
\r
104 TrackName20 equ 40h
\r
105 TrackName21 equ 41h
\r
106 TrackName22 equ 42h
\r
107 TrackName23 equ 43h
\r
108 TrackName24 equ 44h
\r
109 TrackName25 equ 45h
\r
110 TrackName26 equ 46h
\r
111 TrackName27 equ 47h
\r
112 TrackName28 equ 48h
\r
113 TrackName29 equ 49h
\r
114 TrackName2a equ 4ah
\r
115 TrackName2b equ 4bh
\r
116 TrackName2c equ 4ch
\r
117 TrackName2d equ 4dh
\r
118 TrackName2e equ 4eh
\r
119 TrackName2f equ 4fh
\r
121 UnilinkRAD equ 50h ; Beginning of Unilink packet - the Receiving Address
\r
122 UnilinkTAD equ 51h ; Transmitter address
\r
123 UnilinkCMD1 equ 52h ; CMD1 byte
\r
124 UnilinkCMD2 equ 53h ; CMD2 byte
\r
125 UnilinkParity1 equ 54h ; First or only parity byte for short packets (6 bytes)
\r
126 UnilinkData1 equ 55h ; Extra data for medium/large packets, or zero for short packets
\r
127 UnilinkData2 equ 56h ;
\r
128 UnilinkData3 equ 57h ;
\r
129 UnilinkData4 equ 58h ;
\r
130 UnilinkData5 equ 59h ; Data5 if this is a large packet
\r
131 UnilinkParity2M equ 59h ; Parity2 shares the same byte if it's a medium sized packet
\r
132 UnilinkData6 equ 5ah ; Extra data for large packets, or zero for medium packets
\r
133 UnilinkData7 equ 5bh ;
\r
134 UnilinkData8 equ 5ch ;
\r
135 UnilinkData9 equ 5dh ;
\r
136 UnilinkParity2 equ 5eh ; Parity byte for large packets
\r
137 UnilinkZero equ 5fh ; Should always be zero (possibly used to signal corrupt packets from slave to master?)
\r
139 UnilinkTimeout equ 60h ; Counts up every 0.5ms to "age out" faulty bytes clocked in
\r
140 UnilinkSelected equ 61h ; High bit is set when selected
\r
141 UnilinkBit equ 62h ; This is my "bitmask" to be used for requests
\r
142 UnilinkID equ 63h ; This is my Bus ID
\r
143 UnilinkCmdLen equ 64h ; This gets updated with the actual packet length after CMD1 has been received
\r
144 UnilinkTXRX equ 65h ; This is a pointer to the Unilink packet above, used with indirect addressing
\r
145 SlaveBreakState equ 66h ; Hold state and time-out information about slave break, indicates when it can happen
\r
146 DisplayStatus equ 67h ; What information will be put on the display next, bit 7 cleared if nothing
\r
147 Icount equ 68h ; Offset of string to print
\r
148 TxTemp equ 69h ; blahblah
\r
149 TxTemp2 equ 6ah ; Blahblah2
\r
158 DataCount equ 71h ; Temp storage for the bit counter used during bit shifts (Unilink TX/RX)
\r
159 DataStore equ 72h ; This is a kludge
\r
161 IRQPCLATH equ 7dh ; ISH storage
\r
162 IRQSTATUS equ 7eh ; Needs to be located in a shared area accessible from all register banks
\r
165 DiscName00 equ 0a0h ; Buffer for DiscName
\r
166 DiscName01 equ 0a1h
\r
167 DiscName02 equ 0a2h
\r
168 DiscName03 equ 0a3h
\r
169 DiscName04 equ 0a4h
\r
170 DiscName05 equ 0a5h
\r
171 DiscName06 equ 0a6h
\r
172 DiscName07 equ 0a7h
\r
173 DiscName08 equ 0a8h
\r
174 DiscName09 equ 0a9h
\r
175 DiscName0a equ 0aah
\r
176 DiscName0b equ 0abh
\r
177 DiscName0c equ 0ach
\r
178 DiscName0d equ 0adh
\r
179 DiscName0e equ 0aeh
\r
180 DiscName0f equ 0afh
\r
181 DiscName10 equ 0b0h
\r
182 DiscName11 equ 0b1h
\r
183 DiscName12 equ 0b2h
\r
184 DiscName13 equ 0b3h
\r
185 DiscName14 equ 0b4h
\r
186 DiscName15 equ 0b5h
\r
187 DiscName16 equ 0b6h
\r
188 DiscName17 equ 0b7h
\r
189 DiscName18 equ 0b8h
\r
190 DiscName19 equ 0b9h
\r
191 DiscName1a equ 0bah
\r
192 DiscName1b equ 0bbh
\r
193 DiscName1c equ 0bch
\r
194 DiscName1d equ 0bdh
\r
195 DiscName1e equ 0beh
\r
196 DiscName1f equ 0bfh
\r
200 ;----------------------------------------------------------------
\r
201 ; Power up/Reset starting point
\r
203 org 0 ; Start at the beginning of memory (the reset vector)
\r
204 call Bootstrap ; Call Flash Load routine
\r
205 call LCDInit ; Initialize LCD I/F
\r
206 call IRQInit ; Set up and start the IRQ handler
\r
207 goto Main ; Run the main program loop (skip the IRQ handler)
\r
209 subtitl "IRQ Handler"
\r
210 ;----------------------------------------------------------------
\r
211 ; Interrupt handler always starts at addr 4
\r
212 ; In order to reduce the INT latency the actual code is put here directly instead of using a goto instruction.
\r
213 ; Also because of the real-time requirements for clocking data onto the Unilink bus the first check in the ISR
\r
214 ; is to see whether the Unilink clock rise was the reason for the interrupt. This results in a "clock rise to
\r
215 ; bit ready" time of less than 30 instruction cycles, should be plenty of spare time waiting for clock to go low
\r
216 ; again after that. Other interrupts might introduce latencies, but let's see how this works..
\r
218 org 4 ; ISR vector is at address 4
\r
219 movwf IRQW ; Save W
\r
220 swapf STATUS,w ; Get the status register into w
\r
221 clrf STATUS ; Zero out the status reg, gives Reg Bank0
\r
222 movwf IRQSTATUS ; Store the STATUS reg
\r
223 ; Not using PCLATH for anything in the ISR right now
\r
224 ; movf PCLATH,w ; Get the PCLATH reg
\r
225 ; movwf IRQPCLATH ; And store it
\r
226 ; clrf PCLATH ; Go to low memory
\r
227 ; Maybe save FSR here as well (if there's a need for it in the non-ISR code)
\r
229 btfss INTCON,INTF ; Check if it's the INT edge interrupt (Unilink CLK)
\r
230 goto IRQNotINT ; No it's not, check the other sources
\r
232 ; If there's activity on the clock line (the clock goes high) the CPU will stay in here until eight bits have been clocked in
\r
233 ; - this reduces context switching (and it's just a few hundred cpu cycles after all (20us*8 bits=160us=800 instruction
\r
234 ; cycles (5 MIPS @ 20MHz), not even a problem for serial input if it's not receiving more than 6250 bytes per second, and the
\r
235 ; 2-byte FIFO somehow fills up (this should be impossible even @ 115200 as this blocking INT handler only runs a maximum of
\r
236 ; 1000 times per second, halting INT's for 1/6250 of a second - this gives the CPU ample of time to deal with all bytes from
\r
237 ; the USART. I should check the OERR (Serial Overrun) bit to catch this though.. Note that this piece of code does both TX
\r
238 ; and RX at the same time (in order to receive packets one has to make sure that the packet buffer is zeroed out before entering
\r
239 ; here, otherwise collisions will occur..
\r
240 ; According to my logic analyzer this implementation is pretty decent when it comes to timing, even though it's an
\r
241 ; interrupt driven "USART" implemented in software - by trigging the interrupt on the rising edge there's some extra margin here
\r
242 ; (the clock goes high 10us before the master clocks the bit in (on the falling edge), that should be plenty of time..)
\r
244 movlw 8 ; Loop through the 8 bits
\r
246 movf UnilinkTXRX,w ; Get the pointer
\r
247 movwf FSR ; Store it to make use of indirect addressing
\r
250 btfss INDF,7 ; Test high bit of data (that's the first bit to be clocked out)
\r
251 goto IRQINTTristate ; Bit is low, we should tristate bit
\r
252 bcf PORTC,3 ; Otherwise set DATA bit low
\r
253 bsf STATUS,RP0 ; Select high regs
\r
254 bcf TRISC,3 ; And pull low (now it's an output)
\r
255 bcf STATUS,RP0 ; Back to regbank 0
\r
256 goto IRQINTCLKWaitLow ; Wait for master to actually clock this bit in
\r
259 bsf STATUS,RP0 ; Select high regs
\r
260 bsf TRISC,3 ; Force the bit to be tristated
\r
261 bcf STATUS,RP0 ; Back to regbank 0
\r
264 btfss PORTC,2 ; Check for BUSON
\r
266 btfsc PORTB,0 ; Wait for clock to go low
\r
267 goto IRQINTCLKWaitLow
\r
270 btfss PORTC,3 ; Test DATA
\r
271 setc ; Set carry if data is LOW (data is inverted!)
\r
272 rlf INDF,f ; Shift it into the "accumulator"
\r
274 decfsz DataCount,f ; Loop once more perhaps?
\r
275 goto IRQINTCLKWaitHigh ; Yes, again!
\r
276 goto IRQINTRecvDone ; No it's done, don't check for clock to go high again
\r
279 btfss PORTC,2 ; Check for BUSON
\r
281 btfss PORTB,0 ; Wait for clock to go high
\r
282 goto IRQINTCLKWaitHigh
\r
283 goto IRQINTBitSet ; Loop again
\r
285 ; Successfully received a byte here, run it through a state machine to figure out what to do
\r
286 ; (several possibilites exists here):
\r
287 ;;;;;; If more than 1.1ms has passed since last receive, reset receive counter to zero
\r
288 ; If receive counter is zero and the received byte is a zero byte, discard it
\r
289 ; Otherwise store the byte in our receive buffer and increment receive counter
\r
290 ; If the receive counter is 3 check the two upper bits of recv'd byte (CMD1) - this tells us the length of the packet
\r
291 ; 00 = short 6 byte packet
\r
292 ; 10 = medium 11 byte packet
\r
293 ; 11 = long 16 byte packet
\r
294 ; Update the receive length byte accordingly
\r
295 ; Check whether receive length and receive count are equal, that means that we're finished and we can carry on parsing
\r
296 ; the packet and take appropriate action.
\r
299 clrf SlaveBreakState ; First of all, clear the break state - this got in the way, restart detection..
\r
300 movf UnilinkTXRX,w ; Find out which byte # that was received
\r
302 bnz IRQINTRecvNotFirst ; Not the first byte
\r
303 movf UnilinkRAD,w ; Get the first byte received
\r
304 bz IRQINTRecvNullByte ; Null byte received, ignore this, don't increment counter
\r
306 incf UnilinkTXRX,f ; Increment address
\r
308 movf UnilinkTXRX,w ; Get the byte position again
\r
309 andlw 0fh ; Only lower 4 bits of interest
\r
310 xorlw 03h ; Well, is it the third byte? (CMD1, telling us the length of the packet)
\r
311 bnz IRQINTRecvNotCMD1 ; No, skip the length code for now
\r
312 movlw 6 ; Assume it's a short packet
\r
313 btfss INDF,7 ; INDF still points to received byte, test high bit for medium/long
\r
314 goto IRQINTRecvShort ; Nope, it's a short packet
\r
315 addlw 5 ; OK, it's long or medium at least
\r
316 btfsc INDF,6 ; Test for long
\r
317 addlw 5 ; Yep, it's a long packet
\r
319 movwf UnilinkCmdLen ; Store the length
\r
322 movf UnilinkTXRX,w ; Get the byte position
\r
323 xorwf UnilinkCmdLen,w ; XOR with the calculated command length
\r
324 andlw 0fh ; and mask - this results in a zero result when finished receiving
\r
325 bnz IRQINTRecvIncomplete ; Packet not ready yet
\r
327 ; Here a packet is actually received, should check the checksum(s) as well, but I don't care right now
\r
328 ; (I need music in my car! :))
\r
329 ; This is inefficient, I know, I'll improve it later... (Not that it matters, there's plenty of time here
\r
330 ; (there won't be any more communication for at least another 4.8ms))
\r
332 ; Unilink command parser:
\r
334 ; Check for CMD1 = 01h (System bus commands)
\r
337 bnz IRQINTParseNot01
\r
339 ; Check for 01 00 (Bus Re-Initialization)
\r
341 bnz IRQINTParseNot0100
\r
343 call ClearUnilinkStatus ; Clear everything Unilink (ID, BUSON_OUT)
\r
345 goto IRQINTParseComplete ; Don't send any reply to this (clear the packet buffer though)
\r
349 ; Check for 01 02 (Anyone)
\r
352 bnz IRQINTParseNot0102
\r
354 movf UnilinkID,w ; Do I have an ID already?
\r
355 bnz IRQINTParseNot0102 ; Yep, I don't want another one!
\r
357 ; clrf UnilinkParity1
\r
358 call ClearUnilinkBuffer ; Zero it out completely
\r
360 movlw 10h ; Sending to Master
\r
361 addwf UnilinkParity1,f
\r
363 movlw 0d0h ; I'm in the MD changer group
\r
364 addwf UnilinkParity1,f
\r
366 movlw 8ch ; Device discovery command reply
\r
367 addwf UnilinkParity1,f
\r
370 addwf UnilinkParity1,f
\r
373 movf UnilinkParity1,w
\r
374 movwf UnilinkParity2M
\r
376 movlw 24h ; My internal MD sends 25 here first time, and then 24 when appointed!??
\r
377 addwf UnilinkParity2M,f
\r
380 addwf UnilinkParity2M,f
\r
383 addwf UnilinkParity2M,f
\r
385 movlw 0a0h ; 00?? 0a0=10 disc?
\r
386 addwf UnilinkParity2M,f
\r
389 ; clrf UnilinkData6
\r
390 goto IRQINTParseBypassClear ; Don't clear the data, the buffer will be sent as the next packet
\r
394 ; Check for 01 12 (Time poll)
\r
397 bnz IRQINTParseNot0112
\r
400 xorwf UnilinkID,w ; Is it for me?
\r
401 bnz IRQINTParseNot0112 ; Nope
\r
403 ; clrf UnilinkParity1
\r
404 call ClearUnilinkBuffer
\r
405 movlw 10h ; Sending to Master
\r
406 addwf UnilinkParity1,f
\r
408 movf UnilinkID,w ; This is my ID
\r
409 addwf UnilinkParity1,f
\r
412 addwf UnilinkParity1,f
\r
415 movlw 80h ; Idle unless selected
\r
416 btfsc UnilinkSelected,7
\r
419 addwf UnilinkParity1,f
\r
421 ; clrf UnilinkData1
\r
422 goto IRQINTParseBypassClear ; Don't clear the data, the buffer will be sent as the next packet
\r
426 ; Check for 01 13 (Request Time poll)
\r
429 bnz IRQINTParseNot0113
\r
432 xorwf UnilinkID,w ; Is it for me?
\r
433 bnz IRQINTParseNot0113 ; Nope
\r
435 btfss DisplayStatus,7 ; If not displaying, skip this
\r
436 goto IRQINTParseComplete
\r
438 ; clrf UnilinkParity1
\r
439 call ClearUnilinkBuffer
\r
440 movlw 70h ; Sending to Display Group
\r
441 addwf UnilinkParity1,f
\r
443 movf UnilinkID,w ; This is my ID
\r
444 addwf UnilinkParity1,f
\r
447 addwf UnilinkParity1,f
\r
450 addwf UnilinkParity1,f
\r
453 movf UnilinkParity1,w ; Carry the parity forward
\r
454 movwf UnilinkParity2M
\r
457 movf DisplayStatus,w
\r
458 addwf UnilinkParity2M,f
\r
461 addwf UnilinkParity2M,f
\r
464 addwf UnilinkParity2M,f
\r
467 movf DisplayStatus,w
\r
469 addwf UnilinkParity2M,f
\r
472 ; clrf UnilinkData6
\r
474 incf DisplayStatus,f ; Temporary debug info
\r
475 bsf DisplayStatus,7
\r
477 goto IRQINTParseBypassClear ; Don't clear the data, the buffer will be sent as the next packet
\r
481 ; Check for 01 15 (Who sent the slave break?)
\r
484 bnz IRQINTParseNot0115
\r
486 btfss DisplayStatus,7 ; First of all check if there should be anything displayed
\r
487 goto IRQINTParseComplete ; No, not at this time
\r
489 ; clrf UnilinkParity1
\r
490 call ClearUnilinkBuffer
\r
491 movlw 10h ; Sending to Master
\r
492 addwf UnilinkParity1,f
\r
494 movlw 18h ; Broadcast address sending in this special case
\r
495 addwf UnilinkParity1,f
\r
497 movlw 82h ; Who wants to talk reply command
\r
498 addwf UnilinkParity1,f
\r
503 addwf UnilinkParity1,f
\r
506 movf UnilinkParity1,w ; Carry the parity forward
\r
507 movwf UnilinkParity2M
\r
511 addwf UnilinkParity2M,f
\r
515 addwf UnilinkParity2M,f
\r
519 addwf UnilinkParity2M,f
\r
523 addwf UnilinkParity2M,f
\r
526 ; clrf UnilinkData6
\r
528 goto IRQINTParseBypassClear ; Don't clear the data, the buffer will be sent as the next packet
\r
530 ;******************************************************************************
\r
531 ; Bit frig - works out which bit to set in the response to Master Poll
\r
533 ; W register is input of which stage you are on (0x00, 0x20, 0x30, 0x40 etc)
\r
534 ; and is returned with the byte to write (0x00 if wrong stage).
\r
537 xorwf UnilinkBit, 0
\r
538 andlw 0xe0 ; Strip off low bits
\r
540 btfsc STATUS, Z ; Do we have a hit?
\r
547 btfss UnilinkBit, 4 ; Do we need to swap nybbles?
\r
555 swapf UnilinkBit, 0
\r
563 ; Check for CMD1 = 02h (Appoint)
\r
566 bnz IRQINTParseNot02
\r
568 bsf BUSON_OUT_BIT ; Now activate the cascade BUSON pin, to allow others to be discovered
\r
570 movf UnilinkRAD,w ; Get the ID the master has given me
\r
571 movwf UnilinkID ; Store my id
\r
572 movf UnilinkCMD2,w ; Get the bitmask
\r
573 movwf UnilinkBit ; And store it (this is needed when doing slave breaks and actually responding)
\r
575 ; clrf UnilinkParity1
\r
576 call ClearUnilinkBuffer
\r
577 movlw 10h ; Sending to Master
\r
578 addwf UnilinkParity1,f
\r
580 movf UnilinkID,w ; This is my ID
\r
581 addwf UnilinkParity1,f
\r
583 movlw 8ch ; Device discovery command again
\r
584 addwf UnilinkParity1,f
\r
587 addwf UnilinkParity1,f
\r
590 movf UnilinkParity1,w
\r
591 movwf UnilinkParity2M ; That's the parity when sending medium messages
\r
594 addwf UnilinkParity2M,f
\r
596 movlw 0a8h ; My internal MD sends 1c here... (external/internal difference)
\r
597 addwf UnilinkParity2M,f
\r
600 addwf UnilinkParity2M,f
\r
602 movlw 0a0h ; 0a0=10disc
\r
603 addwf UnilinkParity2M,f
\r
606 ; clrf UnilinkData6
\r
607 goto IRQINTParseBypassClear ; Don't clear the data, the buffer will be sent as the next packet
\r
611 ; Check for CMD1 = 87h (Power control)
\r
614 bnz IRQINTParseNot87
\r
616 ; Test for power-on bit (it seems like bit 3 (0x08h) of CMD2 is set when the power is on)
\r
617 btfsc UnilinkCMD2,3
\r
618 goto IRQINTParse87PowerOn
\r
620 bsf RS232_RI_BIT ; Set this to make RI pin go low (after RS-232 levels)
\r
621 goto IRQINTParseComplete
\r
623 IRQINTParse87PowerOn
\r
624 bcf RS232_RI_BIT ; Clear this to make RI pin go high (waking the computer)
\r
625 goto IRQINTParseComplete
\r
629 ; Check for CMD1 = f0h (Source Select)
\r
632 bnz IRQINTParseNotF0
\r
635 xorwf UnilinkID,w ; Check if it's selecting me
\r
636 bnz IRQINTParseF0Deselect
\r
638 bsf UnilinkSelected,7 ; Now we're selected
\r
639 bsf DisplayStatus,7
\r
640 goto IRQINTParseComplete
\r
642 IRQINTParseF0Deselect
\r
644 bcf UnilinkSelected,7 ; Now we're de-selected
\r
645 bcf DisplayStatus,7
\r
646 goto IRQINTParseComplete
\r
650 IRQINTParseComplete
\r
652 ; The code ends up here when parsing is complete and it's not interested in sending any reply back to the master
\r
653 ; (that's why we clear out all the packet buffer bytes)
\r
655 call ClearUnilinkBuffer
\r
657 IRQINTParseBypassClear
\r
659 movlw UnilinkRAD ; Get the pointer to the first byte in the receive buffer
\r
660 movwf UnilinkTXRX ; Store it - this way the next byte that gets received goes into RAD
\r
662 clrf UnilinkCmdLen ; No command length while waiting for a new packet
\r
665 IRQINTRecvIncomplete
\r
669 movwf DataStore ; Store it so the non-irq code can snoop
\r
672 bcf INTCON,INTF ; Clear the IRQ source bit to re-enable INT interrupts again
\r
676 btfss PIR1,TMR2IF ; Check if it's the TMR2 interrupt (0.5ms timing)
\r
677 goto IRQNotTMR2 ; No it's not, check the other sources
\r
679 ; Slave break opportunity detection here - the logic works as follows:
\r
680 ; Look for a data low period of at least 5 ms (10 loops)
\r
681 ; Look for a data high period of at least 2 ms (4 loops)
\r
682 ; If the Slave Break request bit has been set, issue a slave break by holding the data line low for 4ms (8 loops)
\r
683 ; If a bit would be received (CLK activates) the packet handler automatically clears out the SlaveBreakState, which means start all over
\r
685 ; incf Counter,f ; Increment the general purpose counter
\r
687 btfsc SlaveBreakState,5 ; Check if already pulling the data line low
\r
688 goto IRQTMR2SlaveBreak
\r
690 btfsc SlaveBreakState,7 ; Looking for low or high data
\r
691 goto IRQTMR2HighData
\r
692 btfss DATA_BIT ; Looking for a low data line, if it's low, increment state, if it's high, reset state
\r
693 goto IRQTMR2LowDataOK
\r
694 clrf SlaveBreakState ; Got a high data line while waiting for a low one, reset state
\r
695 goto IRQAfterTMR2 ; Leave ISR
\r
698 btfsc DATA_BIT ; Looking for a high data line, if it's high - increment state, otherwise wait
\r
699 goto IRQTMR2HighDataOK
\r
701 btfsc SlaveBreakState,6 ; Test the "first time around" bit
\r
702 clrw ; Not the beginning of the state, have to restart the entire thing now, not just this state
\r
703 andwf SlaveBreakState,f ; Mask out the 1 upper control bits and restart this state
\r
708 bsf SlaveBreakState,6 ; Set the "first time around" bit
\r
710 movf SlaveBreakState,w
\r
713 btfss SlaveBreakState,7 ; Checking whether it's low or high
\r
714 goto IRQTMR2FoundLow
\r
716 xorlw 4 ; It's high now, and if 4 periods have passed we can activate slave break
\r
720 ; Issue slave break here
\r
722 clrf SlaveBreakState
\r
726 btfss DisplayStatus,7 ; Only do this if high bit is set
\r
730 movwf SlaveBreakState
\r
741 movlw 80h ; Prepare for state 2, looking for data line high
\r
742 movwf SlaveBreakState
\r
746 movf SlaveBreakState,w
\r
754 clrf SlaveBreakState
\r
757 btfss SlaveBreakState,4 ; Only increment to 0x10
\r
758 incf SlaveBreakState,f
\r
759 bcf PIR1,TMR2IF ; Clear the IRQ source bit to re-enable TMR2 interrupts again
\r
763 ; Finally restore CPU state and return from the ISR
\r
765 ; If I have to save the FSR in the beginning I also need to restore it here...
\r
768 ; movwf PCLATH ; Restore PCLATH
\r
770 movwf STATUS ; Restore STATUS
\r
772 swapf IRQW,w ; Restore W
\r
773 retfie ; Interrupt return
\r
775 ;----------------------------------------------------------------
\r
776 ; ClearUnilinkStatus - Zeroes out the Unilink state (used when initializing)
\r
780 clrf UnilinkID ; Clear the existing Unilink ID, if any
\r
781 bcf BUSON_OUT_BIT ; Clear the cascade BUSON pin, not activated again until we have a new ID
\r
782 clrf DisplayStatus ; No crazy display updates when resetting.. :)
\r
783 clrf UnilinkSelected ; We're not selected anymore
\r
785 bsf STATUS,RP0 ; Reg bank 1
\r
786 bsf DATA_BIT ; Make sure data is tristated
\r
787 bcf STATUS,RP0 ; Reg bank 0
\r
789 movlw UnilinkRAD ; Get the pointer to the first byte in the receive buffer
\r
790 movwf UnilinkTXRX ; Store it - this way the next byte that gets received goes into RAD
\r
792 clrf UnilinkCmdLen ; No command length while waiting for a new packet
\r
796 ;----------------------------------------------------------------
\r
797 ; ClearUnilinkBuffer - Zeroes out the Unilink packet buffer
\r
801 ; TODO: Replace this with an FSR access to save space and make the code neater
\r
806 clrf UnilinkParity1
\r
816 clrf UnilinkParity2
\r
822 subtitl "Main loop"
\r
825 ;----------------------------------------------------------------
\r
826 ; Main program begins here. [Called after bootloader, lcdinit and irqinit...]
\r
827 ; Here all other house keeping tasks are performed, like displaying info on the LCD..
\r
833 movlw low StartUpText1 ; Show something on the LCD
\r
838 bcf LCD_RS_BIT ; LCD Command mode
\r
839 movlw 80h ; DisplayRam 0
\r
844 movf Counter,w ; Debug timer
\r
845 btfsc PORTA,4 ; Test RST
\r
850 movf SlaveBreakState,w
\r
852 btfsc PORTB,0 ; Test CLK
\r
857 btfsc PORTC,2 ; Test BUSON-IN
\r
862 btfsc PORTC,3 ; Test DATA
\r
866 movf UnilinkCmdLen,w
\r
867 bz MainDontPrintCmd
\r
873 movf DataCount,w ; Load bit counter (if 0 then byte is available)
\r
877 decf DataCount,f ; Set it non-zero
\r
880 call BootTXB ; Send to terminal
\r
884 ;----------------------------------------------------------------
\r
885 ; IRQInit - Sets up the IRQ Handler
\r
886 ; Set up Timer2 to generate 2000 interrupts per second, used for timing - 1/16 prescaler and a PR2 reg of 156 (0x9c) is set
\r
890 ; Start with clearing the Unilink packet buffer before enabling any interrupts, otherwise the first packet might become corrupt
\r
891 ; TODO: Replace this with FSR access
\r
892 clrf UnilinkSelected
\r
901 clrf UnilinkParity1
\r
911 clrf UnilinkParity2
\r
915 movlw UnilinkRAD ; Get the pointer to the first byte in the receive buffer
\r
916 movwf UnilinkTXRX ; Store it
\r
918 clrf SlaveBreakState ; Zero out the status, we're starting from the beginning
\r
920 ; Fix the output state of RI and BUSON_OUT to a safe default
\r
922 bsf RS232_RI_BIT ; RS232 RI should be inactive (inverted logic, a set bit here gives a negative output)
\r
923 bcf BUSON_OUT_BIT ; BUSON_OUT should be disabled for now, must be appointed first
\r
925 movlw 06h ; Timer2 enabled + 1/16 prescaler
\r
928 bsf STATUS,RP0 ; Reg bank 1
\r
930 movlw 09ch ; Timer PR2 reg giving 2000 interrupts per second
\r
933 bcf RS232_RI_BIT ; Both bits should be outputs
\r
934 bcf BUSON_OUT_BIT ;
\r
936 ; The default behavior of RB0/INT is to interrupt on the rising edge, that's what we use...
\r
937 ; bcf OPTION_REG,INTEDG ; We want RB0 to give us an IRQ on the falling edge
\r
939 bsf INTCON,INTE ; Enable the RB0/INT
\r
940 bsf INTCON,PEIE ; Enable the peripheral interrupts
\r
941 bsf PIE1,TMR2IE ; Enable the Timer2 peripheral interrupt
\r
942 bsf INTCON,GIE ; Enable global interrupts
\r
944 bsf TXSTA,TXEN ; Enable UART TX
\r
946 bcf STATUS,RP0 ; Back to bank 0
\r
948 bsf RCSTA,SPEN ; Enable serial port
\r
949 bsf RCSTA,CREN ; Enable UART RX
\r
953 ;----------------------------------------------------------------
\r
954 ; Initialize LCD Controller...
\r
957 clrf PORTB ; First clear PortB data register
\r
958 bsf STATUS,RP0 ; Reg bank 1
\r
959 movlw 001h ; All but RB0 are outputs.
\r
962 bcf OPTION_REG,NOT_RBPU ; Turn on port B pull-up
\r
963 bcf STATUS,RP0 ; Restore Reg bank 0
\r
965 ; This is a standard reset sequence for the LCD controller
\r
967 movlw 160 ; Need to delay for at least 15ms, let's go for 16ms delay
\r
970 movlw 3 ; Write 3 to the LCD
\r
971 call TxLCD ; Send to LCD
\r
972 movlw 50 ; Need to delay for at least 4.1ms, let's go for 5ms delay
\r
975 movlw 3 ; Write 3 to the LCD
\r
977 movlw 10 ; Need to delay for at least 100us, let's go for 1ms delay
\r
980 movlw 3 ; Write 3 to the LCD
\r
982 movlw 10 ; Need to delay for at least 40us, let's go for 1ms delay
\r
985 movlw 2 ; 4-bit interface requested
\r
987 movlw 10 ; Need to delay for at least 40us, let's go for 1ms delay
\r
990 ; Reset sequence ends here
\r
991 ; From this point no delays are needed, now the BUSY bit is valid and the bus I/F is 4 bits
\r
993 movlw 28h ; Function Select + 4-bit bus + 2-line display
\r
996 movlw 0ch ; Display Control + LCD On (No cursor)
\r
999 movlw 01h ; Clear Display
\r
1002 movlw 06h ; Auto Increment cursor position
\r
1007 ;----------------------------------------------------------------
\r
1009 ; Send a string to the LCD.
\r
1014 movlw 80h ; DisplayRam 0
\r
1019 movlw 80h+40 ; DisplayRam 40 (row 2)
\r
1025 ;----------------------------------------------------------------
\r
1027 ; Send a string to the LCD.
\r
1030 ; movwf Icount ; Icount = W
\r
1032 movwf e_LEN ; Move to e_LEN
\r
1034 Txm_lp movf Icount,w ; get the byte
\r
1036 incf Icount,f ; ...else ++Icount (table index)
\r
1037 call TxLCDB ; Send out the byte
\r
1042 ;----------------------------------------------------------------
\r
1043 ; TxLCDB - send a byte to the LCD
\r
1046 movwf TxTemp ; Store byte to send for a while...
\r
1048 bcf temp,0 ; Clear my temp bit
\r
1049 btfss LCD_RS_BIT ; Check if we try the correct reg
\r
1052 bsf temp,0 ; Indicate RS change
\r
1056 call RxLCDB ; Receive byte from LCD, status reg
\r
1058 skpz ; If the bit was set, the zero flag is not
\r
1061 btfsc temp,0 ; If we had to clear RS reset it now
\r
1064 swapf TxTemp,w ; Hi nibble of data to send in lo w bits
\r
1065 call TxLCD ; Send them first...
\r
1066 movf TxTemp,w ; Then we have the low nibble in low w bits
\r
1067 call TxLCD ; And send that one as well
\r
1070 ;----------------------------------------------------------------
\r
1071 ; RxLCDB - recv a byte from the LCD
\r
1074 call RxLCD ; Receive the high nibble
\r
1076 swapf LCDWTmp,f ; Swap it back to file
\r
1077 call RxLCD ; Receive the low nibble
\r
1078 addwf LCDWTmp,w ; Put the nibbles together and return in W
\r
1082 ;----------------------------------------------------------------
\r
1083 ; TxLCD - send a nibble to the LCD
\r
1086 movwf LCDWTmp ; Write nibble to tmp
\r
1087 bcf LCD_DB4_BIT ; Clear previous data
\r
1088 bcf LCD_DB5_BIT ;
\r
1092 btfsc LCDWTmp,0 ; Test bit 0, transfer a set bit to LCD PORT
\r
1094 btfsc LCDWTmp,1 ; Test bit 1, transfer a set bit to LCD PORT
\r
1096 btfsc LCDWTmp,2 ; Test bit 2, transfer a set bit to LCD PORT
\r
1098 btfsc LCDWTmp,3 ; Test bit 3, transfer a set bit to LCD PORT
\r
1101 bsf LCD_E_BIT ; And set E to clock the data into the LCD module
\r
1102 nop ; Let it settle
\r
1103 bcf LCD_E_BIT ; And clear the Enable again.
\r
1104 return ; Returns without modifying W
\r
1106 ;----------------------------------------------------------------
\r
1107 ; RxLCD - recv a nibble from the LCD
\r
1110 clrw ; Clear W register, return data in lower 4 bits
\r
1112 bsf STATUS,RP0 ; Select 2nd reg bank, now TRIS regs can be accessed
\r
1114 bsf LCD_DB4_BIT ; This sets the port bit as an input
\r
1119 bcf STATUS,RP0 ; Back at reg bank 0
\r
1121 bsf LCD_RW_BIT ; Set Read mode for the LCD
\r
1122 bsf LCD_E_BIT ; And set E to clock the data out of the LCD module
\r
1123 nop ; Let the bus settle
\r
1124 btfsc LCD_DB4_BIT ; Transfer a set port bit into W
\r
1126 btfsc LCD_DB5_BIT ; Transfer a set port bit into W
\r
1128 btfsc LCD_DB6_BIT ; Transfer a set port bit into W
\r
1130 btfsc LCD_DB7_BIT ; Transfer a set port bit into W
\r
1132 bcf LCD_E_BIT ; And clear the Enable again.
\r
1133 bcf LCD_RW_BIT ; Set Write mode for the LCD
\r
1135 bsf STATUS,RP0 ; Select 2nd reg bank, now TRIS regs can be accessed
\r
1137 bcf LCD_DB4_BIT ; Set the port as an output again
\r
1138 bcf LCD_DB5_BIT ;
\r
1142 bcf STATUS,RP0 ; Back at reg bank 0
\r
1144 return ; Returns with data in W
\r
1146 ;----------------------------------------------------------------------
\r
1147 ; Delay routines (non-interrupt based, therefore not even close to reliable)
\r
1148 ; W=10 gives ~ 1ms of delay
\r
1149 ; 1ms=5000 instructions wasted, 100us=500 cycles
\r
1150 ; Maximum time waited will be 256*100us=25.6ms
\r
1153 movwf Dcount ; Set delay counter, number of 100us periods to wait
\r
1156 movlw 0a5h ; This gives 165 iterations of the inner loop, wastes 495 cycles + these two + one more
\r
1157 movwf Dcount2 ; exiting the loop + 3 more for the outer loop = 501 cycles for every Dcount
\r
1159 decfsz Dcount2,f ; 1 cycle (or two when exiting the loop)
\r
1160 goto DelayInner ; 2 cycles
\r
1161 decfsz Dcount,f ; Now decrement number of 100us periods and loop again
\r
1166 ;----------------------------------------------------------------
\r
1167 ; Data can be stored between 600 and 6ffh...
\r
1171 DT "----- WJ UniLink"
\r
1175 LookUp movwf PCL ; Go to it (this assumes PCLATH == 06h)
\r
1178 subtitl "Bootstrap/Bootloader code"
\r
1181 ;----------------------------------------------------------------------
\r
1182 ; Bootstrap code - Allows PIC to flash itself with data from the async port.
\r
1183 ; Accepts a standard INHX8 encoded file as input, the only caveat is that the code is slow when writing to memory
\r
1184 ; (we have to wait for the flash to complete), and therefore care has to be taken not to overflow the RS232 receiver
\r
1185 ; (one good way of solving that is to wait for the echo from the PIC before sending anything else)
\r
1186 ; Both program memory and Data EEPROM memory can be programmed, but due to hardware contraints the configuration
\r
1187 ; register can't be programmed. That means that any references to the config register in the hex file will be ignored.
\r
1189 ; Startup @9600bps
\r
1191 ; RAM usage for the bootstrap code
\r
1193 BootBits equ 7eh ; bit0 1=write 0=read, bit1 1=PGM 0=EE, bit2 0=normal 1=no-op when prog
\r
1198 BootTimerL equ 79h
\r
1199 BootTimerM equ 78h
\r
1200 BootTimerH equ 77h
\r
1201 BootNumBytes equ 76h
\r
1202 BootDataVL equ 75h
\r
1203 BootDataVH equ 74h
\r
1204 BootHEXTemp equ 73h
\r
1206 org 738h ; Place the boot code at the top of memory (currently the loader is exactly 200 bytes)
\r
1209 bsf STATUS,RP0 ; Access bank 1
\r
1210 bsf TXSTA,TXEN ; Enable UART TX
\r
1211 movlw 31 ; Divisor for 9k6 @ 20MHz Fosc
\r
1212 movwf SPBRG ; Store
\r
1213 bcf STATUS,RP0 ; Back to bank 0
\r
1215 bsf RCSTA,SPEN ; Enable serial port
\r
1216 bsf RCSTA,CREN ; Enable UART RX
\r
1218 movlw low BootStartText ; Send boot banner to the serial port
\r
1221 movlw 0e8h ; Initialize timeout timer
\r
1227 incf BootTimerL,f ; A 24-bit counter
\r
1232 skpnz ; When overflowing here..
\r
1233 goto BootReturn ; ..Exit boot loader, no keypress within timeout period, resume program
\r
1234 btfss PIR1,RCIF ; Wait for RX to complete
\r
1239 goto BootTimeout ; If it wasn't ESC, wait for another key
\r
1242 movlw low BootFlashText ; OK, flashing it is, send "start" text to serial port
\r
1250 call BootRXB ; First find the ':'
\r
1253 goto BootLoop ; Loop until we find it!
\r
1255 call BootRXHEX ; Get one ASCII encoded byte (two chars)
\r
1256 movwf BootNumBytes ; This is the number of bytes to be programmed on the line
\r
1257 ; Maybe clear cary here?
\r
1258 rrf BootNumBytes,f ; Right shift because we're double addressing this 8-bit format
\r
1260 ; Note carry should be clear here as there cannot be odd number of bytes in this format
\r
1262 call BootRXHEX ; Receive AddrH
\r
1264 call BootRXHEX ; Receive AddrL
\r
1266 rrf BootAddrH,f ; Fix the addressing again
\r
1269 bcf BootBits,2 ; Assume we should program
\r
1270 bsf BootBits,1 ; And assume we should program flash not ee
\r
1273 xorlw 020h ; Check if it's configuration, which we can't program
\r
1274 skpnz ; Skip the bit set if it was false alarm
\r
1275 bsf BootBits,2 ; No programming for this line
\r
1277 xorlw 001h ; Also check if it's EEPROM memory (first xor 20h then 1 =21h)
\r
1278 skpnz ; Skip the bit set instr if not EE data address
\r
1279 bcf BootBits,1 ; We should program EE, will ignore the AddrH
\r
1281 call BootRXHEX ; Receive Record Type (must be 0 for real records)
\r
1282 skpz ; Check if zero
\r
1283 goto BootFlashComplete
\r
1286 call BootRXHEX ; Receive low-byte of data word
\r
1288 call BootRXHEX ; Receive high-byte of data word
\r
1291 btfsc BootBits,2 ; Check whether this line should be programmed at all
\r
1292 goto BootWriteSkip
\r
1294 bcf BootBits,0 ; Read mode first, verify if we actually have to write
\r
1297 xorwf BootDataL,f ; Compare and destroy DataL
\r
1298 movwf BootDataL ; Write new data to DataL
\r
1299 skpz ; Skip if no difference, have to check high byte as well
\r
1300 goto BootWrite ; Jump directly to write
\r
1303 xorwf BootDataH,f ; Compare
\r
1304 skpnz ; Skip if no difference, no programming necessary
\r
1305 goto BootWriteSkip
\r
1309 movwf BootDataH ; Have to put the new H byte data in as well
\r
1312 call BootEE ; Write directly into program mem
\r
1314 ; Here a verify can take place, the read-back results are now in DataL/H
\r
1318 incf BootAddrL,f ; Advance counter to next addr
\r
1320 incf BootAddrH,f ; And add to high byte if needed
\r
1322 decfsz BootNumBytes,f
\r
1330 movlw low BootRunText
\r
1333 bsf STATUS,RP0 ; Reg bank 1
\r
1335 btfss TXSTA,TRMT ; Wait for last things to flush
\r
1336 goto BootReturnWait
\r
1337 bcf TXSTA,TXEN ; Disable UART TX
\r
1338 bcf STATUS,RP0 ; Back to bank 0
\r
1340 bcf RCSTA,SPEN ; Disable serial port
\r
1341 bcf RCSTA,CREN ; Disable UART RX
\r
1343 return ; Return to code
\r
1345 ;----------------------------------------------------------------------
\r
1346 ; BootTXB - Sends one byte to the UART, waits for transmitter to become
\r
1347 ; free before sending
\r
1351 btfss PIR1,TXIF ; Wait for TX to empty
\r
1353 movwf TXREG ; Send the byte
\r
1356 ;----------------------------------------------------------------------
\r
1357 ; BootTXStr - Sends ASCII string pointed to by W, zero terminated
\r
1360 movwf BootAddrL ; Store LSB of text pointer
\r
1361 movlw 07h ; MSB of pointer to the text (0700h in this boot loader)
\r
1363 movlw 02h ; Select "Read Program Memory" operation
\r
1366 call BootEE ; Lookup char (actually two packed into one word)
\r
1367 rlf BootDataL,w ; Shift the MSB out into carry (that's the 2nd char LSB)
\r
1368 rlf BootDataH,w ; Shift it into 2nd char
\r
1369 call BootTXB ; Send the high byte first
\r
1370 movf BootDataL,w ; Get the low byte
\r
1371 andlw 07fh ; Mask of the highest bit
\r
1372 skpnz ; Stop if zero
\r
1374 call BootTXB ; Send char
\r
1375 incf BootAddrL,f ; Increment pointer
\r
1376 goto BootTXStrLoop
\r
1378 ;----------------------------------------------------------------------
\r
1379 ; BootRXB - Receives one byte from the UART, waits if nothing available
\r
1383 btfss PIR1,RCIF ; Wait for RX to complete
\r
1385 movf RCREG,w ; Get the recvd byte
\r
1386 call BootTXB ; Echo to terminal
\r
1389 ;----------------------------------------------------------------------
\r
1390 ; BootRXHEXNibble - Receives one byte and converts it from ASCII HEX to binary
\r
1393 call BootRXB ; Receive nibble
\r
1394 addlw -'A' ; Convert from BCD to binary nibble
\r
1395 skpc ; Test if if was 0-9 or A-F, skip if A-F
\r
1396 addlw 'A' - 10 - '0' ; It was numeric '0'
\r
1397 addlw 10 ; Add 10 (A get to be 0ah etc.)
\r
1400 ;----------------------------------------------------------------------
\r
1401 ; BootRXHEX - Receives two bytes from the UART, waits if nothing available
\r
1402 ; Decodes the bytes as ASCII hex and returns a single byte in W
\r
1405 call BootRXHEXNibble
\r
1407 swapf BootHEXTemp,f ; Swap it up to the high nibble
\r
1409 call BootRXHEXNibble
\r
1410 addwf BootHEXTemp,w ; And add the two nibbles together
\r
1413 ;----------------------------------------------------------------------
\r
1414 ; BootEE - Reads or writes EE or Flash memory, BootBits specify the
\r
1415 ; exact action to take. BootAddrL and BootAddrH has to be initialized
\r
1416 ; to the address of choice (0000-003fh for EE and 0000h-07ffh for flash
\r
1417 ; The data to be written has to be put in BootDataL and BootDataH, and
\r
1418 ; data will be to the same place when read back
\r
1421 bsf STATUS,RP1 ; Select bank 2 (RP0 must be 0)
\r
1423 movf BootAddrH,w ; Load desired address
\r
1427 movf BootDataH,w ; And load the data (only used when writing)
\r
1432 bsf STATUS,RP0 ; Go to bank 3
\r
1434 bsf EECON1,EEPGD ; Point to Program Flash mem
\r
1435 btfss BootBits,1 ; Test if that was correct or if we have to clear again
\r
1436 bcf EECON1,EEPGD ; Point to EE DATA mem
\r
1438 btfss BootBits,0 ; Check from read or write
\r
1439 goto BootEERD ; Skip the WR if we were going for a read
\r
1441 bsf EECON1,WREN ; Enable writes
\r
1445 movwf EECON2 ; Unlock write operation
\r
1446 bsf EECON1,WR ; And start a write cycle
\r
1448 btfsc EECON1,WR ; This executes for EE only not flash, waits for WR to finish
\r
1449 goto BootWRLoop ; These two instructions gets NOPed when flashing
\r
1451 bcf EECON1,WREN ; Finally disable writes again
\r
1452 ; Here we read the data back again, can be used as verify
\r
1454 bsf EECON1,RD ; Start a read cycle
\r
1455 nop ; Only necessary for flash read, same thing as when writing above
\r
1456 nop ; Except I could use the two words for something useful there.. :)
\r
1459 bcf STATUS,RP0 ; Back to bank 2
\r
1460 movf EEDATA,w ; Store our EE-data
\r
1464 bcf STATUS,RP1 ; And finally back to bank 0
\r
1468 ; To produce compact code the end zero byte has to be in the LSB (that means an even number of chars in every string)
\r
1470 DW 0x2bca,0x216f,0x37f4,0x102d,0x1070,0x3965,0x39f3,0x1045,0x29c3,0x1074,0x37a0,0x336c,0x30f3,0x3400
\r
1471 ; DE "WJBoot - press ESC to flash\x00"
\r
1473 DW 0x068a,0x29e5,0x3764,0x1049,0x2748,0x2c38,0x1066,0x34ec,0x32a0,0x376f,0x3bae,0x172e,0x0680
\r
1474 ; DE "\r\nSend INHX8 file now...\r\x00"
\r
1476 DW 0x068a,0x22f8,0x34f4,0x34ee,0x33a0,0x366f,0x30e4,0x32f2,0x0680
\r
1477 ; DE "\r\nExiting loader\r\x00"
\r
1480 ;----------------------------------------------------------------------
\r
1481 ; EE Data (64 bytes), located at 2100h
\r
1484 ; de 0ffh, 0ffh, 0ffh, 0ffh, 0ffh, 0ffh, 0ffh, 0ffh
\r