From: ian <ian>
Date: Tue, 22 Feb 2005 22:18:38 +0000 (+0000)
Subject: i2c slave debugging:  faff a bit with led settings in slave pic; make master panic... 
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ijackson/git?a=commitdiff_plain;h=243cc9c44a0b6a376b3492992173dba3e1e2e848;p=trains.git

i2c slave debugging:  faff a bit with led settings in slave pic; make master panic immediately after doing START (for testing); clarify comments re SSPCON1 value; slave SSPCON1 value is more correct
---

diff --git a/cebpic/i2c-test.asm b/cebpic/i2c-test.asm
index 20b6ce7..58b6bea 100644
--- a/cebpic/i2c-test.asm
+++ b/cebpic/i2c-test.asm
@@ -240,8 +240,9 @@ slave_main
 
 slave_main_loop
 	call 	wait_for_i2c_interrupt	; wait for 1st (address) byte
+	call	led_green
 	call 	wait_for_i2c_interrupt	; wait for 2nd (data) byte
-	btg	TRISD,2,0        	; toggle LED on/off
+	call	led_black
 	goto	slave_main_loop
 
 ;----------------------------------------
@@ -255,6 +256,7 @@ serial_rx_isr
 	call 	wait_for_i2c_interrupt
 
 	debug	'e'
+	call	panic
 
 	movlw	0x41			; transmit address 0100 0001
 	movwf	SSPBUF,0
@@ -390,8 +392,8 @@ i2c_setup
 	goto	i2c_setup_if_slave
 
 i2c_setup_if_master
-	movlw	0x08
-	movwf	SSPCON1,0	; set to master mode, clear top 4 bits
+	movlw	0x08		; clear top 2 status bits; disable SSP;
+	movwf	SSPCON1,0	;  CKP unused, set to 0; master mode.
 
 ; set baud rate
 	movlw	100-1
@@ -402,10 +404,10 @@ i2c_setup_if_master
 	goto	i2c_setup_endif_master_slave
 
 i2c_setup_if_slave
-	movlw	0x06
-	movwf	SSPCON1,0	; set to 7bit slave mode, clear top 4 bits
-				; (no extra start/stop interrupts)
-	!!fixme probably want to set SSPCON2:SEN "clock stretching"
+	movlw	0x16		; clear top 2 status bits; disable SSP;
+	movwf	SSPCON1,0	;  release clock; 7bit slave mode with
+				;  no extra start/stop interrupts.
+;	!!fixme probably want to set SSPCON2:SEN "clock stretching"
 
 ; set slave address
 	banksel	PIC_NO		; set BSR=i2c BSR (4)