frisc_dma.frisc

; FRISC DMA io unit example
; =========================
;
; A FRISC DMA unit is mapped to 6 word-length
; locations starting from 0xFFFF0000 and is
; connected to INT0. However, the unit is not
; working in interrupt mode.
; 
; The program transfers 1000 4-byte words from
; an IO unit mapped on 0xFFFF3330 to memory
; starting from location 0x4000, using halting
; transfer mode.

DMA_SRC `EQU 0FFFF0000
DMA_DEST `EQU 0FFFF0004
DMA_SIZE `EQU 0FFFF0008
DMA_CTRL `EQU 0FFFF000C
DMA_START `EQU 0FFFF0010
DMA_ACK `EQU 0FFFF0014

; Initialize stack pointer to 0x10000

 MOVE 10000, SP

; initialize DMA unit
; destin=mem, source=VJ, halt, no INT

 MOVE 0FFFF3330, R0
 STORE R0, (DMA_SRC)
 MOVE 4000, R0
 STORE R0, (DMA_DEST)
 MOVE %D 1000, R0
 STORE R0, (DMA_SIZE)
 MOVE %B 0100, R0 
 STORE R0, (DMA_CTRL)

; start DMA transfer

 STORE R0, (DMA_START)

; acknowledge DMA transfer end and halt CPU

 STORE R0, (DMA_ACK) ; brisanje statusa DMA
 HALT