IBM AT 5170 Technical Reference page 350

IBM Persona! Computer MACRO Assembler Version 2.00
1-'
BIOS2 ---- 06/10/85 BIOS INTERRUPT ROUTINES
06-10-85
228 alOE E8 o 16B R
CALL UPD IPR CHECK FOR UPDATE I N PROCESS
229 o I I I
13 03
JNC
RTC-65
SKIP INITIALIZATION IF NO ERROR
230 01 13 E8 0154 R
CALL
RTC::::STA ELSE INITIALIZE CLOCK
231 0116 RTC 65:
2'2
01 16 8A E5 MOV
AH,DH
GET SECONDS BYTE
-
233
a
I 18 BO 01 MOV
AL, CMOS SEC ALARM ADDRESS THE SECONDS ALARM REG [STER
2'4
a
I
IA E8 0000 E
CALL
CMOS WRITE -
I NSERT SECONDS
235 0110 8A EI MOV
AH,CC GET MINUTES PARAMETER
2'5
01 IF BO 0' MOV
AL, CMOS MIN ALARM ADDRESS MINUTES ALARM REGISTER
237
0121 E8 0000 E
CALL CMOS WRTTE - INSERT MINUTES
2'8
0124 8A E5 MDV
AH,cFi GET HOURS PARAMETER
239 0126 80 05 MDV
AL, CMOS HR ALARM ADDRESS HOUR ALARM REG
I
STER
240 0128 E8 0000 E CALL CMOS WRTTE ­
I NSERT HOURS
241 012B E4 AI
IN AL,INTBOI READ SECOND
I
NTERRUPT MASK REGISTER
242 0120 24 FE
AND AL,OFEH ENABLE ALARM T I MER BIT I CY= 0)
24'
012F E6 AI OUT
INTBO I ,AL WRITE UPDATED MASK
244 0131 B8 OBOB MOV
ADDRESS ALARM REG [STER
245
0134 E8 0000 E
CALL READ CURRENT ALARM REG [STER
~~o~*~~~~_REG_B
245 0137 24 1F AND
AL,OlFH ENSURE SET
81
T TURNED OFF
241 0139 DC 20 OR
AL,20H TURN ON ALARM ENABLE
248 0138 86 EO
XCHG
AH,AL MOVE MASK TO OUTPUT REG I STER
249 013D E8 0000 E
CALL
CMOS_WR I TE
WR
I
TE NEW ALARM MASK
250 0140 F8 eLe
SET CY= 0
251 0141 RTe 69 :
-
252
0141
B8 0000 MDV
AX,O CLEAR AX REG I STER
25'
0144 C3
RET RETURN WITH RESULTS
[N
CARRY FLAG
254
255 0145 RTC 70:
RESET ALARM
-
255 0145 88 OB08
MOV AX.X*CMOS REG B ADDRESS ALARM REGISTER (TO 80TH AH,AL)
251
0148 E8 0000 E CALL CMOS READ- -
READ ALARM REG I STER
258 014B 24 51
AND AL,51H TURN OFF ALARM ENABLE
259 0140 86 EO
XCHG AH,AL
SAVE DATA AND RECOVER ADDRESS
250 014F E8 0000 E CALL
CMOS_WR I TE RESTORE NEw VALUE
25 I 0152 F8
CLC SET CY= 0
252 0153 C3
RET RETURN WITH NO CARRY
25'
264 0154
RTC_OO
ENDP
255
255 0154
RTC STA PROC NEAR
INITIALIZE REAL TIME CLOCK
-
251 0154 88 260A
MOV
AX,26H*H+CMOS REG A ADDRESS REGISTER A AND LOAD DATA MASK
258 0157 E8 0000 E
CALL
CMOS WRITE - -
INITIALIZE STATUS REGISTER A
259 a 15A B8 820B
MOV AX,82H-H+CMOS REG B
SET ·SET
BIT"
FOR CLOCK INITIALIZATION
210 0150 E8 0000 E
CALL
CMOS WR I TE - -
AND 24 HOUR MODE TO REG I STER B
211 0160 BO OC
MOV AL. CMOS REG C ADDRESS REGISTER C
212
0162 E8 0000 E
CALL CMOS READ -
READ REGISTER C TO INITIALI ZE
21'
0165 BO 00 MOV
AL. CMOS REG
0 ADDRESS REGISTER D
214
0167 E8 0000 E CALL CMOS_READ -
READ REG I STER
D
TO
I
N I TI AL.I ZE
215 a 16A C3
RET
215
211
0168 RTC STA ENDP
218
219
o
16B UPD IPR PROC
NEAR WA ITT I LL UPDATE NOT I N PROGRESS
280 0168 51
PUSH CX SAVE CALLERS REGI STER
281 016C 89 0320 MDV
cX,eoo SET TIMEOUT LOOP COUNT
282 016F UPD 10:
-
-
28'
a 16F 80 OA MOV
AL,CMOS_REG_A
ADDRESS STATUS REG I STER A
284 0111 FA
CL I NO TIMER INTERRUPTS DURING UPDATES
285 0172 E8 0000 E
CALL CMOS READ READ UPDATE IN PROCESS FLAG
285 0115 A8 80
TEST
AL,8QH IF UIP BIT IS ON I CANNOT READ TIME)
281 Of 77 14 05
JZ UPD_90 EXIT WITH CY= 0 IF CAN READ CLOCK NOW
288
0119 FB
ST! ALLOW [NTERRUPTS WH I LE WA I T [NG
289
Ol7A E2 F' LOOP
UPD 10 LOOP TILL READY OR TIMEOUT
290 017C 33 CO
XOR
AX.Ax CLEAR RESULTS I F ERROR
291 ailE F9
STC
SET CARRY FOR ERROR
292 OllF
UPD 90:
-
293 o 11F 59
POP
CX RESTORE CALLERS REG I STER
294
0180 FA
CLI I NTERRUPTS OFF OUR I NG SET
295 0181 C,
RET RETURN WITH CY FLAG SET
296
291 0182
UPD
-
IPR ENDP
5-178
BIOS2