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EXTERNAL BUS INTERFACE
17
17-5
32185/32186 Group Hardware Manual
Rev.1.10 REJ09B0235-0110 May 15, 07
17.2 External Bus Interface Related Registers
The following describes the external bus interface related registers.
17.2.1 Port Operation Mode and Port Peripheral Function Select Registers
Ports P0–P4 (except P41–P43), P124, P125, P224 and P225 are switched for external access signal pins
during external extension mode when so set by the corresponding Operation Mode Register. During processor
mode, these ports always function as external access signal pins.
During external extension mode, these pins are switched for port upon exiting reset. Therefore, by switching the
pin functions for only those pins that are needed for external access, the remaining pins can be used as port.
Ports P70–P73, P126, P127, P150, P153, P220 and P221 can be switched for external access signal pins at
any time irrespective of the CPU operation mode. Ports P41–P43 always function as external access signal
pins during external extension and processor modes.
P0 Operation Mode Register (P0MOD)
<Address: H’0080 0740>
<Upon exiting reset: H’00>
b
Bit Name
Function
R
W
0
P00MD
0: P00/DD0 (Note 1)
R
W
Port P00 operation mode bit
1: DB0/TO21 (Note 2)
1
P01MD
0: P01/DD1 (Note 1)
R
W
Port P01 operation mode bit
1: DB1/TO22 (Note 2)
2
P02MD
0: P02/DD2 (Note 1)
R
W
Port P02 operation mode bit
1: DB2/TO23 (Note 2)
3
P03MD
0: P03/DD3 (Note 1)
R
W
Port P03 operation mode bit
1: DB3/TO24 (Note 2)
4
P04MD
0: P04/DD4 (Note 1)
R
W
Port P04 operation mode bit
1: DB4/TO25 (Note 2)
5
P05MD
0: P05/DD5 (Note 1)
R
W
Port P05 operation mode bit
1: DB5/TO26 (Note 2)
6
P06MD
0: P06/DD6 (Note 1)
R
W
Port P06 operation mode bit
1: DB6/TO27 (Note 2)
7
P07MD
0: P07/DD7 (Note 1)
R
W
Port P07 operation mode bit
1: DB7/TO28 (Note 2)
Note 1: The port and DD input functions both are effective. To use the port as DD input pin, set the port direction for input.
Note 2: Which function of the pin is used depends on how the P0 Peripheral Function Select Register is set.
Note: During processor mode, settings of this register have no effect, and the ports function as external bus interface signal
pins (DB0-DB7).
17.2 External Bus Interface Related Registers
b0
12
3456
b7
P00MD
P01MD
P02MD
P03MD
P04MD
P05MD
P06MD
P07MD
000
0000
0