Example 71. initializing the refresh control unit – Intel 80C188XL User Manual

Page 190

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7-11

REFRESH CONTROL UNIT

Example 7-1. Initializing the Refresh Control Unit

$mod186

name

example_80C186_RCU_code

; FUNCTION: This function initializes the DRAM Refresh

; Control Unit to refresh the DRAM starting at dram_addr

; at clock_time intervals.

; SYNTAX:

; extern void far config_rcu(int dram_addr, int clock_time);

; INPUTS:

dram_addr - Base address of DRAM to refresh

;

clock_time - DRAM refresh rate

; OUTPUTS:

None

;

NOTE: Parameters are passed on the stack as

;

required by high-level languages.

RFBASE

equ xxxxh

;substitute register offset

RFTIME

equ xxxxh

RFCON

equ xxxxh

Enable

equ 8000h

;enable bit

lib_80186

segment public 'code'

assume cs:lib_80186

public _config_rcu

_config_rcu

proc far

push bp

;save caller's bp

mov bp, sp

;get current top of stack

_clock_time

equ word ptr[bp+6]

;get parameters off

_dram_addr

equ word ptr[bp+8]

;the stack

push ax

;save registers that

push cx

;will be modified

push dx

push di

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