From a94b68175866789ba4a69cb5ddbe2b80ce2b92fa Mon Sep 17 00:00:00 2001
From: ian <ian>
Date: Wed, 21 Dec 2005 15:44:18 +0000
Subject: [PATCH] i2cmu_read_got_byte - main scanning loop - wip

---
 detpic/mascan.asm     | 67 +++++++++++++++++++++++++++++++++++++++++--
 detpic/morse.messages |  1 +
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/detpic/mascan.asm b/detpic/mascan.asm
index b80e107..f1d4f25 100644
--- a/detpic/mascan.asm
+++ b/detpic/mascan.asm
@@ -2,8 +2,35 @@
 ; MASTER - SCANNING ETC.
 
  include common.inc
- code
 
+ udata_acs
+
+cslot	res	1	; current slave in slave table, points to flags byte
+main	res	1
+	; one of the following:
+	;	0000 0000	we're expecting the first byte
+	;	
+	;	M0BB 0001	we have rec
+	;	M0BB 0001	we have rec
+
+	;	MM zz B2 B1 zz zz zz II
+	;
+	;	main byte from slave
+; X0BB0000
+			; where X is 1 iff we're expecting an `extra byte'
+			; otherwise NN is the detection byte we're expecting
+
+sc		res	1
+sc_extra	equ	7 ; we're 
+
+slavetable_section udata 0x280
+slavetable res maxpics * 2
+	; each entry is:
+	;  1 byte slave number
+	;  1 byte flags
+	;	00DD0000	where D is 1 iff a detectors board
+
+ code
 ;======================================================================
 
 ;----------------------------------------
@@ -16,8 +43,44 @@ i2cm_intrl
 	intrl_handled_nostack
 
 ;----------------------------------------
-i2cmu_done
 i2cmu_read_got_byte
+;   		Beforehand	At call
+;   State	Reading		Reading-Wait
+;   W				data from slave
+;
+; See detect.asm head comment for protocol info, in particular
+; the meaning of these bytes.
+	mov_wf	t		; remember the byte for a moment
+	mov_lw	slavetable >> 8
+	mov_wf	FSR1H
+	mov_ff	cslot, FSR1L
+
+	tst_f_ifnz cbyte
+	bra	read_got_notfirst
+	; this is a first (head) byte:
+
+	and_wfw	POSTINC1, 
+	
+
+	bt_f_if1 cbyte, 4
+	bra	read_got_moredet1
+	bt_f_if1 cbyte, 5
+	bra	read_got_moredet2
+	
+	
+	mov_fw	cbyte
+	
+	bra_n	read_got_extra
+	bra_nz	read_got_moredet
+
+	bt_f_if1 sc, sc_extra
+	bra	got_read_extra
+
+got_read_extra
+	panic	morse_UX
+
+;----------------------------------------
+i2cmu_done
 i2cmu_write_next_byte
 	panic	morse_UI
 
diff --git a/detpic/morse.messages b/detpic/morse.messages
index 82083a3..8a02152 100644
--- a/detpic/morse.messages
+++ b/detpic/morse.messages
@@ -48,6 +48,7 @@ UM
 UE
 UC
 UI
+UX
 
 # Messages for i2clib, S*
 SM	i2clib:st,:sspstat,:sspcon1,:sspcon2 ; m.,i., ctrlr bad state
-- 
2.30.2