read write buf ptr handling

git-svn-id: https://svn.spreadspace.org/mur.sat@210 7de4ea59-55d0-425e-a1af-a3118ea81d4c

1 files changed, 108 insertions, 14 deletions

diff --git a/software/idm/idm.asm b/software/idm/idm.asm
index c1a3ed3..a4fd653 100644
--- a/software/idm/idm.asm
+++ b/software/idm/idm.asm
@@ -41,7 +41,11 @@
 BUF_PAGE_LEN  EQU H'0050'
 BUF_PAGE_CNT  EQU H'0004'
 BUF_OFFSET    EQU H'0020'
-  
+
+  ;; FLAGS
+UNDERRUN      EQU .0
+OVERRUN       EQU .1
+
   ;; I/O Pins
 ;; PortA
 MPU_INT       EQU .4
@@ -55,7 +59,8 @@ MPU_INT       EQU .4
   ;;     all pages
 TMP           EQU H'0070'
 WAIT_CNT      EQU H'0071'
-
+FLAGS         EQU H'0072'
+  
 WBUF_PAGE_PTR EQU H'0074'
 WBUF_PAGE_NUM EQU H'0075'
 RBUF_PAGE_PTR EQU H'0076'
@@ -99,10 +104,13 @@ int_tmr2_adcon
   goto      int_tmr2_adcon
 
   call      wbuf_next
+  btfsc     FLAGS,OVERRUN
+  goto      int_tmr2_end
   movf      ADRESH,w
-  movwf     IND
-;  movwf     TXREG
-  
+  movwf     INDF
+  movwf     TXREG
+
+int_tmr2_end
   bcf       PIR1,TMR2IF
   goto      interrupt_end
   
@@ -173,8 +181,8 @@ init
   movwf     PIE1
   clrf      PIE2
 ;  movlw     .250        ;; 8kHz
-;  movlw     .200        ;; 5kHz
-  movlw     .156        ;; ~50Hz
+  movlw     .200        ;; 5kHz
+;  movlw     .156        ;; ~50Hz
   movwf     PR2
   clrf      ADCON1
   
@@ -184,8 +192,8 @@ init
   movlw     b'10010000'
   movwf     RCSTA
 ;  movlw     b'00000100' ;; 8kHz
-;  movlw     b'00001100' ;; 5kHz
-  movlw     b'01111110' ;; ~50Hz
+  movlw     b'00001100' ;; 5kHz
+;  movlw     b'01111110' ;; ~50Hz
   movwf     T2CON
   movlw     b'01000000'
   movwf     INTCON
@@ -195,11 +203,8 @@ init
   
 ;  bcf       PORTA,MPU_INT
 
-  movlw     BUF_PAGE_LEN - 1
-  movwf     WBUF_PAGE_PTR
-  movlw     BUF_PAGE_CNT - 1
-  movwf     WBUF_PAGE_NUM
-
+  call      wbuf_reset
+  call      rbuf_reset
   clrf      TMP
   bsf       INTCON,GIE
 
@@ -256,7 +261,33 @@ uart_rx_fe
   return
 
   ;; -------------------
+wbuf_reset
+  movlw     BUF_PAGE_LEN - 1
+  movwf     WBUF_PAGE_PTR
+  movlw     BUF_PAGE_CNT - 1
+  movwf     WBUF_PAGE_NUM
+  bcf       FLAGS,OVERRUN
+  
+  ;; -------------------
 wbuf_next
+  btfsc     FLAGS,UNDERRUN
+  goto      wbuf_move_ptr
+  
+  movf      RBUF_PAGE_NUM,w
+  xorwf     WBUF_PAGE_NUM,w
+  btfss     STATUS,Z
+  goto      wbuf_move_ptr
+
+  movf      RBUF_PAGE_PTR,w
+  xorwf     WBUF_PAGE_PTR,w
+  btfss     STATUS,Z
+  goto      wbuf_move_ptr
+
+  bsf       FLAGS,OVERRUN
+  return
+  
+wbuf_move_ptr
+  bcf       FLAGS,UNDERRUN
   movf      WBUF_PAGE_PTR,f
   btfsc     STATUS,Z
   goto      wbuf_next_page
@@ -291,6 +322,69 @@ wbuf_fill_fsr
   bsf       STATUS,IRP
   return
 
+    ;; -------------------
+rbuf_reset
+  movlw     BUF_PAGE_LEN - 1
+  movwf     RBUF_PAGE_PTR
+  movlw     BUF_PAGE_CNT - 1
+  movwf     RBUF_PAGE_NUM
+  bsf       FLAGS,UNDERRUN
+  
+  ;; -------------------
+rbuf_next
+  btfsc     FLAGS,OVERRUN
+  goto      rbuf_move_ptr
+
+  movf      WBUF_PAGE_NUM,w
+  xorwf     RBUF_PAGE_NUM,w
+  btfss     STATUS,Z
+  goto      rbuf_move_ptr
+
+  movf      WBUF_PAGE_PTR,w
+  xorwf     RBUF_PAGE_PTR,w
+  btfss     STATUS,Z
+  goto      rbuf_move_ptr
+
+  bsf       FLAGS,UNDERRUN
+  return
+  
+rbuf_move_ptr
+  bcf       FLAGS,OVERRUN
+  movf      RBUF_PAGE_PTR,f
+  btfsc     STATUS,Z
+  goto      rbuf_next_page
+  decf      RBUF_PAGE_PTR,f
+  goto      rbuf_fill_fsr
+
+rbuf_next_page
+  movlw     BUF_PAGE_LEN - 1
+  movwf     RBUF_PAGE_PTR
+  movf      RBUF_PAGE_NUM,f
+  btfsc     STATUS,Z
+  goto      rbuf_next_cycle
+  decf      RBUF_PAGE_NUM,f
+  goto      rbuf_fill_fsr
+
+rbuf_next_cycle
+  movlw     BUF_PAGE_CNT - 1
+  movwf     RBUF_PAGE_NUM
+  
+rbuf_fill_fsr
+  movlw     BUF_OFFSET
+  addwf     RBUF_PAGE_PTR,w
+  movwf     FSR
+
+  btfss     RBUF_PAGE_NUM,0
+  bcf       FSR,7
+  btfsc     RBUF_PAGE_NUM,0
+  bsf       FSR,7
+  btfss     RBUF_PAGE_NUM,1
+  bcf       STATUS,IRP
+  btfsc     RBUF_PAGE_NUM,1
+  bsf       STATUS,IRP
+  return
+
+
   ;; -------------------------------------
   ;; MAINLOOP
 main