Cirrus Logic AN130 - Manual (Page 6)

AN130
6 AN130REV2
8. APPENDIX: PIC16C84 MICROCODE TO INTERFACE TO THE CS5521/22/23/24/28
;*****************************************************************************
;* File:
55221684.ASM
;* Date: November 1, 1999
;* Revision: 1
;* Processor:PIC16C84
;* Program entry point at routine "main". Entry point address is 0x05.
;*****************************************************************************
;* This program is designed to provide examples of how to interface the
;* CS5521/22/23/24/28 ADCs to a PIC16C84 Microcontroller. The software handles all
;* of the serial communications between the controller and the ADC to perform
;* system calibration and acquire 24 and 16-bit conversion words.
;*****************************************************************************
;*** Memory Map Equates ***
STATUS equ 0x03 ; STATUS register
PORTA equ 0x05 ; I/O Port A address
TRISA equ 0x85 ; Port A Data Direction Control Latch
CARRY equ 0x00 ; Carry Bit in STATUS
RP0 equ 0x05 ; Register Bank Select Bit in STATUS
CS equ 0x00 ; Port A bit 0 - Chip Select
SDI equ 0x01 ; Port A bit 1 - Serial Data In
SDO equ 0x02 ; Port A bit 2 - Serial Data Out
SCLK equ 0x03 ; Port A bit 3 - Serial Clock
HIGHBYTE equ 0X0C ; Upper 8 Bits of Conversion Register
MIDBYTE equ 0x0D ; Middle 8 Bits of Conversion Register
LOWBYTE equ 0x0E ; Lowest 8 bits of Conversion Register
COMMAND equ 0x0F ; Command Byte RAM location
TEMP equ 0x10 ; Temporary Data storage RAM location
COUNT equ 0x11 ; Software Counter RAM location
SERI_DATA equ 0x12 ; Serial Data RAM location
;*****************************************************************************
;* Program Code
;*****************************************************************************
processor 16C84 ; Set Processor Type
org 0x00 ; Reset Vector Location
goto main ; Start at "main" routine
;*****************************************************************************