From: ian <ian>
Date: Mon, 3 Jan 2005 23:09:00 +0000 (+0000)
Subject: comments and halfway read through -iwj
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ijackson/git?a=commitdiff_plain;h=0c9074e41b9b1629b656131eb7282ff0afa10e3c;p=trains.git

comments and halfway read through -iwj
---

diff --git a/cebpic/nmra-stream.asm b/cebpic/nmra-stream.asm
index 63d92f7..adb3264 100644
--- a/cebpic/nmra-stream.asm
+++ b/cebpic/nmra-stream.asm
@@ -49,6 +49,7 @@ debug macro debugvalue
 	endm
 
 debug_serial_transmit
+*** check and wait for flag so that it works if we debug twice in quick succession -iwj
 	movwf	TXREG,0		; move contents of W (i.e. debugvalue) to TXREG for transmission
 	return
 
@@ -136,10 +137,14 @@ initialise
 ; interrupt set-up for serial receive
 	bsf	PIE1,5,0	; enable USART receive interrupt (p85)
 	bsf	IPR1,5,0	; set to low-priority interrupt
+*** surely we should set the priority before enabling it, or you might
+***  generate a spurious high-priority interrupt  -iwj
 
 ; interrupt set-up for timer0 interrupt p79/80
 	bsf	INTCON,5,0	; enable timer0 interrupts
 	bcf	INTCON2,2,0	; timer0 overflow low priority
+*** surely we should set the priority before enabling it, or you might
+***  generate a spurious high-priority interrupt  -iwj
 
 
 ;*****************************************************************************************
@@ -147,6 +152,7 @@ initialise
 main_loop_led
 	call	led_green
 	goto	main_loop_led
+*** do you really mean to set the led green in a tight loop ?? -iwj
 
 
 ;*****************************************************************************************
@@ -168,6 +174,7 @@ interrupt_low
 
 ; if 2 interrupts are set at once the 2nd will generate a new interrupt on leaving
 ; the interrupt routine
+; *** we hope and trust -iwj
 
 
 ;*****************************************************************************************
@@ -178,6 +185,7 @@ serial_receive
 	movwf	FSR0H,0			; set high byte of IND0 pointer
 	movff	RCREG,IND0		; copy to received register
 	incf	FROMSERIAL,1,0		; advance FROMSERIAL pointer by 1 byte
+; *** check for overrun and do something sensible
 	btfss	RCREG,7,0		; check if bit 7 is set
 	call	advance_write_buffer	; if so, move to next buffer
 	retfie	1
@@ -263,6 +271,8 @@ decide_next_bit
 read_from_buffer
 
 ; if currently on bit 7, want to skip to bit 6
+*** wouldn't it be easier to start on bit 6 ? :-)  -iwj
+*** have read up to here -iwj
 
 	btfss	TOTRACKBIT,7,0
 	rrncf	TOTRACKBIT,1,0		; rotate mask right
diff --git a/detpic/nmra-stream.asm b/detpic/nmra-stream.asm
index 63d92f7..adb3264 100644
--- a/detpic/nmra-stream.asm
+++ b/detpic/nmra-stream.asm
@@ -49,6 +49,7 @@ debug macro debugvalue
 	endm
 
 debug_serial_transmit
+*** check and wait for flag so that it works if we debug twice in quick succession -iwj
 	movwf	TXREG,0		; move contents of W (i.e. debugvalue) to TXREG for transmission
 	return
 
@@ -136,10 +137,14 @@ initialise
 ; interrupt set-up for serial receive
 	bsf	PIE1,5,0	; enable USART receive interrupt (p85)
 	bsf	IPR1,5,0	; set to low-priority interrupt
+*** surely we should set the priority before enabling it, or you might
+***  generate a spurious high-priority interrupt  -iwj
 
 ; interrupt set-up for timer0 interrupt p79/80
 	bsf	INTCON,5,0	; enable timer0 interrupts
 	bcf	INTCON2,2,0	; timer0 overflow low priority
+*** surely we should set the priority before enabling it, or you might
+***  generate a spurious high-priority interrupt  -iwj
 
 
 ;*****************************************************************************************
@@ -147,6 +152,7 @@ initialise
 main_loop_led
 	call	led_green
 	goto	main_loop_led
+*** do you really mean to set the led green in a tight loop ?? -iwj
 
 
 ;*****************************************************************************************
@@ -168,6 +174,7 @@ interrupt_low
 
 ; if 2 interrupts are set at once the 2nd will generate a new interrupt on leaving
 ; the interrupt routine
+; *** we hope and trust -iwj
 
 
 ;*****************************************************************************************
@@ -178,6 +185,7 @@ serial_receive
 	movwf	FSR0H,0			; set high byte of IND0 pointer
 	movff	RCREG,IND0		; copy to received register
 	incf	FROMSERIAL,1,0		; advance FROMSERIAL pointer by 1 byte
+; *** check for overrun and do something sensible
 	btfss	RCREG,7,0		; check if bit 7 is set
 	call	advance_write_buffer	; if so, move to next buffer
 	retfie	1
@@ -263,6 +271,8 @@ decide_next_bit
 read_from_buffer
 
 ; if currently on bit 7, want to skip to bit 6
+*** wouldn't it be easier to start on bit 6 ? :-)  -iwj
+*** have read up to here -iwj
 
 	btfss	TOTRACKBIT,7,0
 	rrncf	TOTRACKBIT,1,0		; rotate mask right