VersaLogic STD32 VL-1225, Справочное руководство

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VL-1225/6 Analog Input/Output Board
6-5
Analog Output
The following example outputs zero volts to D/A channel 1. It is assumed that the board is addressed at
I/O location 0300H, and the output channel is jumpered for two’s complement format.
The key program section is:
WRITE
Outputs the value 80h (zero volts) to D/A channel number 1.
;VL-1225 REGISTER ADDRESSES
= 0300 istat equ 00300h ;Interrupt Status Register
= 0300 ictrl equ 00300h ;Interrupt Control Register
= 0303 select equ 00303h ;Input Channel Select Register
= 0304 idlow equ 00304h ;Input Data Low Register
= 0305 idhigh equ 00305h ;Input Data High Register
= 0306 od0 equ 00306h ;Channel 0 Output Data Register
= 0307 od1 equ 00307h ;Channel 1 Output Data Register
0000 code segment para public ‘CODE’
assume cs:code
0000 write: ;OUTPUT ZERO VOLTS ON CHANNEL 1
0000 BA 0307 mov dx,od1 ;Select channel 1
0003 B0 80 mov al,80h ;80h = Zero volts in 2’s complement mode
0005 EE out dx,al ;Output data to D/A converter
0006 code ends
end write
Software Examples – Analog Output