Philips CEM2100/00, Руководство по обслуживанию

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5CL8
5.7 Port P6 (P67 to P60)
Port P6 is an 8-bit input/output port which can be configured as an input or output in one-bit unit.
Port P6 is also used as an analog input and key-on wakeup input.
Input/output mode is specified by the P6 control register (P6CR1) and P6 input control register (P6CR2).
During reset, the P6CR1 is initialized to "0" the P6CR2 is initialized to "1" and port P6 becomes an input mode.
And the P6DR is initialized to "0".
When used as an output port, the corresponding bit of P6CR1 should be set to "1".
When used as an input port , the corresponding bit of P6CR1 should be set to "0" and then, the corresponding bit of
P6CR2 should be set to "1".
When used as a key-on wakeup input , the corresponding bit of P6CR1 should be set to "0" and then, the corre-
sponding bit of STOPkEN should be set to "1".
When used as an analog input, the corresponding bit of P6CR1 should be set to "0" and then, the corresponding bit
of P6CR2 should be set to "0".
When P6CR1 is "1", the content of the corresponding output latch is read by reading P6DR.
Note: Asterisk (*) indicates “1” or “0” either of which can be selected.
Table 5-4 Register Programming for Multi-function Ports
Function
Programmed Value
P6DR P6CR1 P6CR2 STOPkEN
Port input * “0” “1” *
Key-on wakeup input * "0" * "1"
Analog input * “0” “0” *
Port “0” output “0” “1” * *
Port “1” output “1” “1” * *
Table 5-5 Values Read from P6DR and Register Programming
Conditions
Values Read from P6DR
P6CR1 P6CR2
“0” “0” “0”
“0” “1” Terminal input data
“1”
“0”
Output latch contents
“1”