| ??? 09/25/07 07:00 Read: times |
#144950 - AT89c2051 power up sequence |
Problem reading signature byte of at89c2051.The power up sequence during programming is as follows according to data sheet.
SETB P3.3 ;2051 RST LOW
CALL DELAYL ;10ms delay
CALL DELAYL
CLR P3.3 ;2051 RST HIGH
;PC SET TO 00H
CLR P1.0 ;2051 XTAL1 LOW
SETB P3.6 ;ALE HIGH
SETB P3.7 ;12V OFF
MOV P0,#0FFH
MOV A,#0H ;SIGNATURE READ LOGIC
MOV P2,A
MOV A,P0
CJNE A,#1EH,ERR
MOV 43H,#02H ;20 PIN IC
CLR P1.0 ;NEXT ADDRESS 01H
NOP ;
SETB P1.0 ;
NOP ;
CLR P1.0 ;
MOV A,P0
CJNE A,#11H,S3
MOV 40H,#04H ;1051
JMP BEG
S3:
CJNE A,#21H,S4
MOV 40H,#05H ;2051
JMP BEG
S4:
CJNE A,#41H,ERR
MOV 40H,#06H ;4051
JMP BEG
|
| Topic | Author | Date |
| AT89c2051 power up sequence | 01/01/70 00:00 | |
| any schematics? | 01/01/70 00:00 | |
| No schematics right now | 01/01/70 00:00 | |
| at least... | 01/01/70 00:00 | |
| Single step | 01/01/70 00:00 | |
| And what was it, then? | 01/01/70 00:00 | |
| RE: And what was it, then? | 01/01/70 00:00 | |
| what LCD? | 01/01/70 00:00 | |
| RE: what LCD | 01/01/70 00:00 | |
| OK so why was the LCD blank? | 01/01/70 00:00 | |
| RE: OK so why was the LCD blank? | 01/01/70 00:00 | |
| data conflict/posting pictures | 01/01/70 00:00 | |
| RE:data conflict/posting pictures | 01/01/70 00:00 | |
| Schematics | 01/01/70 00:00 | |
| Complete schematic | 01/01/70 00:00 | |
| please use smaller pictures and png/gif | 01/01/70 00:00 | |
| Done | 01/01/70 00:00 | |
| Using 2051 | 01/01/70 00:00 | |
| make a full terminal from U3 | 01/01/70 00:00 | |
| Add some diodes | 01/01/70 00:00 | |
| RE:Add some diodes | 01/01/70 00:00 | |
| Multiplexing | 01/01/70 00:00 | |
| Pull ups | 01/01/70 00:00 | |
| Not required. | 01/01/70 00:00 | |
try this code | 01/01/70 00:00 |