AM8530H AMD [Advanced Micro Devices], AM8530H Datasheet - Page 167

• Manufacturer Part Number: AM8530H
• Description: Serial Communications Controller
• Manufacturer: AMD [Advanced Micro Devices]

7-18
AMD
7.5.1.2 Initialization Routines
The sample assembly initialization routine, Figure 7-9 takes into account the READ/ WRITE
recovery time and has been tested in an 8 MHz system. The interrupt service routines for
Channel B are for testing only and are not intended as realistic examples. Also, Figure 7-
10 shows a sample initialization sequence written in "C."
AMC AMDOS 8/8 64K, Version 2.00 - 9/26/80
type int8530.a86
;
;
;
;
;
;
;
;
CMD
DATA
TAB
ET
START:
RPT:
;PROGRAM CONTINUES AS DESIRED
TABLE
ETB:
END
THIS ROUTINE WRITTEN FOR THE 8086
INITIALIZES THE 8530 SCC FOR ASYNCHRONOUS
OPERATION AT 9600 BAUD.
REGISTER USAGE
AX
BX
DX
BP
EQU
EQU
EQU
EQU
ORG
MOV
IN
MOV
MOV
MOV
OUT
INC
MOV
OUT
INC
DEC
JZ
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
DB
INPUT AND OUTPUT DATA
COUNTER
ADDRESS OF PORT
POINTER TO MEMORY
0F902H
0F900H
OFFSET TABLE
OFFSET ETB
0100H
DX,CMD
AL,DX
BX,ET-TAB
BP,TAB
AL,[BP]
DX,AL
BP
AL,[BP]
DX,AL
BP
BX
RPT
009H
0C0H
003H
041H
004H
04CH
005H
028H
00BH
056H
00CH
00CH
00DH
000H
00EH
007H
Figure 7-9. SCC Initialization
;COMMAND/STATUS PORT
;DATA PORT
;GET ADDRESS OF CMD PORT
;READ STATUS TO SET STATE
;GET TABLE LENGTH
;POINT TO TABLE
;GET DATA FROM TABLE
;OUTPUT ADDRESS OF REGISTER
;INCREMENT TABLE POINTER
;GET DATA
;OUTPUT DATA TO REGISTER
;INCREMENT TABLE POINTER
;COUNT-1
;REPEAT IF NOT DONE
;ADDRESS WR9
;RESET COMMAND
;ADDRESS WR3
;# OF BITS ETC.
;ADDRESS WR4
;DATA
;ADDRESS WR5
;BITS/CHAR AND TXEN
;ADDRESS WR11
;SELECT BAUD GEN
;ADDRESS WR12
;UPPER TC
;ADDRESS WR13
;LOWER TC
;ADDRESS WR14
;SET DTR AND ENABLE BAUD GEN
SCC Application Notes