From: ian <ian>
Date: Mon, 14 Feb 2005 02:48:17 +0000 (+0000)
Subject: die correctly if _lack_ of ack; debug values right way round
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ijackson/git?a=commitdiff_plain;h=3bca88d90f9bddd36c16e8193bb574d51b087182;p=trains.git

die correctly if _lack_ of ack; debug values right way round
---

diff --git a/cebpic/i2c-test.asm b/cebpic/i2c-test.asm
index 86f54c8..fa92b70 100644
--- a/cebpic/i2c-test.asm
+++ b/cebpic/i2c-test.asm
@@ -118,18 +118,18 @@ debughf macro register
 
 debughf_subroutine
 	call	debughf_digit
-	swapf	DEBUGHF_VALUE,1,0
 	call	debughf_digit
 	return
 
 ;--------------------
 debughf_digit
-;	transmits bottom nybble of DEBUGHF_VALUE in hex
-;	through serial port, as above
+;	transmits top nybble of DEBUGHF_VALUE in hex
+;	through serial port, as above, and swaps nybbles
 ;			Before		After
 ;	W		any		undefined
-; DEBUGHF_VALUE		xxxxDDDD	preserved
+; DEBUGHF_VALUE		BBBBaaaa	aaaaBBBB	(BBBB was sent)
 
+	swapf	DEBUGHF_VALUE,1,0
 	movf	DEBUGHF_VALUE,0,0
 	andlw	0x0f
 	sublw	10
@@ -263,11 +263,11 @@ serial_rx_isr
 
 	debug	'f'
 
-	btfss	SSPCON2,ACKSTAT,0	; check for ack from slave (=0), if no
+	btfsc	SSPCON2,ACKSTAT,0	; check for ack from slave (=0), if no
 	goto 	panic			; then panic, else
 	movff	RCREG,SSPBUF		; copy byte from serial to i2c buffer
 	call 	wait_for_i2c_interrupt
-	btfss	SSPCON2,ACKSTAT,0	; check for ack from slave (=0), if no
+	btfsc	SSPCON2,ACKSTAT,0	; check for ack from slave (=0), if no
 	goto 	panic			; then panic, else
 	bsf	SSPCON2,PEN,0		; i2c STOP
 	call 	wait_for_i2c_interrupt