| ??? 10/08/08 06:56 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#158925 - as long as it is on one port... Responding to: ???'s previous message |
Štěpán,
Stepan Janota said:
I have two the same devices, one on pin P2.0 and another on pin P2.1. [...]I have defined bit variable " DS1820 BIT P2.2 " It's quite unlikely you will have success with ANY of the devices, if you use a pin not connected to any of them... ;-) However, as long as both pins are on the same port, you can pass a "parameter" in form of a mask, e.g.:
DS1820_1_MASK EQU 01h ;P2.0
DS1820_2_MASK EQU 02h ;P2.1
DS1820_3_MASK EQU 04h ;P2.2
[...]
MOV R2,#DS1820_2_MASK
CALL DS1820_RCV_BYTE
[...]
DS1820_RCV_BYTE:
MOV R5,#8
DS1820_RCV1:
MOV A,R2 ;CLR BIT
CPL A
ANL P2,A
NOP
NOP
CPL A ;SET BIT
ORL P2,A
[...]
JW PS. Please have a look at http://www.8052.com/faqs.phtml?FAQ=120199 |
| Topic | Author | Date |
| Routine parameter for port pin | 01/01/70 00:00 | |
| write two different routines! | 01/01/70 00:00 | |
as long as it is on one port... | 01/01/70 00:00 |