From: ian <ian>
Date: Sun, 25 Dec 2005 13:03:27 +0000 (+0000)
Subject: i2cmu_done and i2c_arrange_something initial implementation
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ijackson/git?a=commitdiff_plain;h=ad0b48a0eac3df228408fca991c0533edf51d506;p=trains.git

i2cmu_done and i2c_arrange_something initial implementation
---

diff --git a/detpic/mascan.asm b/detpic/mascan.asm
index fa8c679..92ce973 100644
--- a/detpic/mascan.asm
+++ b/detpic/mascan.asm
@@ -6,6 +6,7 @@
 ;----------------------------------------------------------------------
  udata_acs
 
+; for reading and detection:
 b	res	1	; byte just read
 cslot	res	1	; current slave in slave table, points to flags byte
 cbyte	res	1
@@ -15,10 +16,33 @@ cbyte	res	1
 	;	M010 0000	we're expecting more detection byte 2
 	;	1000 0000	we're expecting an extra byte
 
- code
 ;======================================================================
 ; HANDLING OF I2C EVENTS
 
+near_getwritebyteyes code
+;----------------------------------------
+getwritebyte_yes
+	pop		; we don't care where we were in i2cmu_write_next_byte
+	bc_f	STATUS, Z	; yes, we want to write this byte
+	return		; from i2cmu_write_next_byte
+	
+ code
+;----------------------------------------
+i2cmu_write_next_byte
+	; add calls to getwritebyte_<foo> here:
+	call	getwritebyte_polarity
+	call	getwritebyte_points
+	; end of list of calls to getwritebyte_<foo>
+	; so, no-one wants this slave:
+	bs_f	STATUS, Z
+	return
+
+	bra_nz	write_another_slave
+
+	
+
+	return
+
 ;----------------------------------------
 i2cm_intrl
 ; handles i2c interrupt using i2cm_interrupt[_definite],
@@ -28,13 +52,6 @@ i2cm_intrl
 	call	i2cm_interrupt_definite
 	intrl_handled_nostack
 
-;----------------------------------------
-i2cmu_done	panic	morse_MD
-
-;----------------------------------------
-i2cmu_write_next_byte
-	panic	morse_UI
-
 ;======================================================================
 ; PROCESSING OF INCOMING BYTES - CORE AND DETECTION
 
@@ -183,8 +200,39 @@ i2c_arrange_next_byte
 ; DECIDING WHICH SLAVE TO ADDRESS
 ;...
 i2c_arrange_something
+i2cmu_done
 ; figure out what to do next - which pic to address, etc.
-	panic	morse_UG
+	mov_fw	needwrite_slave
+	bra_nz	arrange_write
+
+	; add calls to needwrite_<foo> here:
+	call	needwrite_polarity
+	call	needwrite_points
+	; end of list of calls to needwrite_<foo>
+
+	; no writing needed, we have to read:
+	mov_lfsr slavetable, 1	; FSR1H -> slavetable
+	mov_ff	cslot, FSR1L	; FSR1 -> current ste_flags
+	mov_lw	ste_size	; W = ste_size
+nextslave_loop
+	add_wff	FSR1L		; FSR1 -> next ste_flags
+	bt_f_if0 INDF1, stf_present
+	bra	nextslave_loop
+
+nextslave_reloop_resume
+	mov_ff	FSR1L, cslot	; cslot -> new ste_flags
+	bt_f_if1 POSTDEC1, stf_sentinel ; FSR1 -> ste_slave
+	bra	nextslave_reloop
+
+	mov_fw	INDF1		; W = new slave number
+	goto	i2cm_read_start
+
+nextslave_reloop
+	mov_lfsr slavetable + ste_size + ste_flags
+	bra	nextslave_reloop_resume
+
+fixme do not i2cm_read_start if no room in buffer
+fixme check that we don't accidentally skip reading a slave
 
 ;======================================================================
 ; PROCESSING OF INCOMING BYTES - EXTRA (NON-DETECTION)
diff --git a/detpic/variables.asm b/detpic/variables.asm
index e0380c8..18681e3 100644
--- a/detpic/variables.asm
+++ b/detpic/variables.asm
@@ -27,6 +27,8 @@ isr_high_save_fsr0	res	2 ; for isrh_fsr0_{save,restore}
 
 xdebug			res	8
 
+; for writing to slaves:
+cwslave			res	1 ; slave we're currently actually writing to
 needwrite_slave		res	1 ; 0 means we don't need to write to any slave
 				  ; non-0 means at least this slave
 				  ; and perhaps others
@@ -79,6 +81,8 @@ ste_detmsgh	equ 7 ; dk 1 001 1 000 being 1 001 Y SSS
 ;			  .k	entry is constant, created during init'n
 ; flags in ste_flags:
 stf_detect	equ 7 ; Gk  this is a detectors board
+stf_sentinel	equ 6 ; Gk  sentinel slot at end of table
+stf_detpresent	equ 5 ; dk  this board has some detectors (or slot is sentinel)
 
  include final.inc