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authorChristian Pointner <equinox@mur.at>2012-06-06 00:40:07 +0000
committerChristian Pointner <equinox@mur.at>2012-06-06 00:40:07 +0000
commit61428482f2b6222c7e95e9483eedafd9f5611661 (patch)
tree24572005b1af796b966ff46d4e32cc409a682005
parentminor fixes (diff)
added ringbuffer ptr handling
git-svn-id: https://svn.spreadspace.org/mur.sat@505 7de4ea59-55d0-425e-a1af-a3118ea81d4c
-rw-r--r--software/idm/idm.asm118
1 files changed, 114 insertions, 4 deletions
diff --git a/software/idm/idm.asm b/software/idm/idm.asm
index d36422a..2b796fd 100644
--- a/software/idm/idm.asm
+++ b/software/idm/idm.asm
@@ -31,6 +31,10 @@
;; -------------------------------------
;; DEFINES
;; constants
+BUF_STARTH EQU 020h
+BUF_STARTL EQU 000h
+BUF_ENDH EQU 023h
+BUF_ENDL EQU 0BFh
;; I/O Pins
;; PortA
@@ -49,10 +53,17 @@ FILTER_EN EQU .7
;; variables
;; all Pages
-CNT0 EQU H'0070'
-CNT1 EQU H'0071'
-CNT2 EQU H'0072'
-TMP EQU H'0073'
+CNT0 EQU H'0070'
+CNT1 EQU H'0071'
+CNT2 EQU H'0072'
+TMP EQU H'0073'
+
+FLAGS EQU H'007F'
+
+ ;; bits
+;; FLAGS
+UNDERRUN EQU .0
+OVERRUN EQU .1
;; -------------------------------------
;; OFFSET
@@ -80,6 +91,105 @@ int_spi
retfie
;; -------------------------------------
+ ;; SUBROUTINES
+wbuf_reset
+ movlw BUF_STARTH
+ movwf FSR0H
+ movlw BUF_STARTL
+ movwf FSR0L
+ bcf FLAGS,OVERRUN
+ return
+
+ ;; -------------------
+wbuf_next
+ btfsc FLAGS,UNDERRUN
+ goto wbuf_move_ptr
+
+ movf FSR1H,w
+ xorwf FSR0H,w
+ btfss STATUS,Z
+ goto wbuf_move_ptr
+
+ movf FSR1L,w
+ xorwf FSR0L,w
+ btfss STATUS,Z
+ goto wbuf_move_ptr
+
+ bsf FLAGS,OVERRUN
+ return
+
+wbuf_move_ptr
+ bcf FLAGS,UNDERRUN
+ addfsr FSR0,1
+
+ movf FSR0H,w
+ sublw BUF_ENDH
+ btfss STATUS,C
+ goto wbuf_wraparound
+ btfss STATUS,Z
+ return
+ movf FSR0L,w
+ sublw BUF_ENDL
+ btfsc STATUS,C
+ return
+
+wbuf_wraparound
+ movlw BUF_STARTH
+ movwf FSR0H
+ movlw BUF_STARTL
+ movwf FSR0L
+ return
+
+
+ ;; -------------------
+rbuf_reset
+ movlw BUF_STARTH
+ movwf FSR1H
+ movlw BUF_STARTL
+ movwf FSR1L
+ bsf FLAGS,UNDERRUN
+
+ ;; -------------------
+rbuf_next
+ btfsc FLAGS,OVERRUN
+ goto rbuf_move_ptr
+
+ movf FSR0H,w
+ xorwf FSR1H,w
+ btfss STATUS,Z
+ goto rbuf_move_ptr
+
+ movf FSR0L,w
+ xorwf FSR1L,w
+ btfss STATUS,Z
+ goto rbuf_move_ptr
+
+ bsf FLAGS,UNDERRUN
+ return
+
+rbuf_move_ptr
+ bcf FLAGS,OVERRUN
+ addfsr FSR1,1
+
+ movf FSR1H,w
+ sublw BUF_ENDH
+ btfss STATUS,C
+ goto rbuf_wraparound
+ btfss STATUS,Z
+ return
+ movf FSR1L,w
+ sublw BUF_ENDL
+ btfsc STATUS,C
+ return
+
+rbuf_wraparound
+ movlw BUF_STARTH
+ movwf FSR1H
+ movlw BUF_STARTL
+ movwf FSR1L
+ return
+
+ ;; -------------------------------------
;; INIT
init
;; BANK 4