From: ceb <ceb>
Date: Sun, 6 Feb 2005 23:25:25 +0000 (+0000)
Subject: changes to flash byte order in README.protocol
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ijackson/git?a=commitdiff_plain;h=5b6b0e494db6a3c2071b14b4f0049ca2c52a0272;p=trains.git

changes to flash byte order in README.protocol

test program for TBLRD from flash memory
---

diff --git a/cebpic/README.protocol b/cebpic/README.protocol
index 52b880e..8a7c399 100644
--- a/cebpic/README.protocol
+++ b/cebpic/README.protocol
@@ -22,12 +22,13 @@ Flash memory ID locations
 =========================
 
 Byte 20 0000h
+		PIC number (guaranteed to be in range 0..63 inclusive)
+
+Byte 20 0001h
 		bit 0		1 for the main PIC (#0)
 				0 otherwise
 		1-7		currently unused, set to 0
 
-Byte 20 0001h
-		PIC number (guaranteed to be in range 0..63 inclusive)
 
 I2C
 ===
diff --git a/cebpic/i2c-test.asm b/cebpic/i2c-test.asm
index baffa73..d12325f 100644
--- a/cebpic/i2c-test.asm
+++ b/cebpic/i2c-test.asm
@@ -16,7 +16,25 @@ FROMSERIAL	equ	0x1	; byte 1: from-serial buffer location (in BSR5)
 TOTRACK		equ	0x2	; byte 2: to-track buffer location (in BSR5)
 TOTRACKBIT	equ	0x3	; byte 3: bit location of pointer within byte
 
-BUFFERPAGE	equ	5
+NMRA_BUFF_PAGE	equ	5
+
+; flash locations for PIC-dependent info:
+
+F_PIC_NO_U	equ	20h	; flash location of PIC number
+F_PIC_NO_H	equ	00h
+F_PIC_NO_L	equ	00h
+
+F_I2C_CTRL_U	equ	20h	; flash location of i2c control byte
+F_I2C_CTRL_H	equ	00h
+F_I2C_CTRL_L	equ	01h
+
+; i2c specifit stuff
+
+I2C_BUFF_PAGE	equ	4	; put i2c relevant stuff into buffer page 4
+PIC_NO		equ	00h	; pic no goes to 400h
+I2C_CTRL	equ	01h	; i2c ctrl bit goes to 401h
+
+
 
 
 	ifdef	SLOW_VERSION
@@ -106,6 +124,29 @@ initialise
 	bcf	IPR1,5,0	; set to low-priority interrupt
 
 
+;----------------------------------------------------------------------------
+
+; copy PIC-dependent info out of flash memory
+
+	movlw	F_PIC_NO_U	; set table pointer to point to
+	movwf	TBLPTRU		; PIC number in flash
+	movlw	F_PIC_NO_H
+	movwf	TBLPTRH
+	movlw	F_PIC_NO_L
+	movwf	TBLPTRL
+
+	tblrd	*+		; read then increment pointer 
+				; (now points to i2c control byte)
+
+	movlb	I2C_BUFF_PAGE	; ser BSR=i2c BSR (4)
+	movff	TABLAT, PIC_NO	; move pic number into normal memory
+
+	tblrd	*		; read i2c 
+
+	movff	TABLAT, I2C_CTRL	; move i2c_ctrl byte into normal memory
+
+; now have: PIC number in 400h, i2c control byte in 401h
+
 ;----------------------------------------------------------------------------
 
 ; i2c setup