Specifications

Application Examples
PUT ICU_MASK,ICU_MASK_INIT
; RESTORE THE REGISTER STATUS
POP DX
POP AX
ICU_INIT ENDP
;
V40 DMA CONTROLLER PROCEDURE
; THE V40 DMA CONTROLLER IS USED FOR HIGH SPEED DATA TRANSFERS
; BETWEEN AN SBX EXPANSION MODULE THAT SUPPORTS DMA AND EITHER
; DUAL PORT OR LOCAL RAM. THE APPROXIMATE DATA RATE FOR TRANS-
; FERS BETWEEN THE EXPANSION MODULE AND RAM USING STANDARD INPUT
; AND OUTPUT INSTRUCTIONS IS 235 KBYTES PER SECOND. USING DMA,
; THE TRANSFER RATE IS INCREASED TO APPROXIMATELY 1.3 MBYTES PER
; SECOND, FOR A PERFORMANCE INCREASE OF OVER 80 PERCENT. THE
; FIRST PROCEDURE IS A GENERAL PURPOSE INITIALIZATION ROUTINE
; THAT PROGRAMS THE FOLLOWING:
;
; DCU ENABLED
; BASE ADDRESS OF 00D0H
; DMA ENABLED
;
; INPUTS: NONE
; OUTPUTS: DMA CONTROLLER INITIALIZED
; CALLS: NONE
; DESTROYS: FLAGS
DCU_INIT PROC
; PRESERVE REGISTER CONTENTS
PUSH AX
PUSH DX
; INITIALIZE V40 CONFIG REGS
PUT OPSEL,OPSEL_INIT_D
PUT OPHA,OPHA_INIT
PUT DULA,DULA_INIT
; INITIALIZE DMA CONTROLLER
PUT DCU_DICM,DCU_DICM_INIT
PUT DCU_DCH,DCU_DCH_INIT
PUT DCU_DDC,DCU_DDC_INIT
; RESTORE THE REGISTER STATUS
POP DX
POP AX
DCU_INIT ENDP
; ONCE THE DMA CONTROLLER IS INITIALIZED, IT IS PROGRAMMED FOR
; DMA WRITE TRANSFERS WITH THE FOLLOWING PROCEDURE. A DMA
; WRITE DEFINES THE SBX I/O AS THE DATA SOURCE AND THE RAM
; MEMORY AS THE DESTINATION. NOTE THAT EITHER DUAL PORT OR
; LOCAL RAM MAY BE USED AS RAM MEMORY. THE FOLLOWING
; PARAMETERS ARE SELECTED:
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