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I/O Ports
15-21
Port 3 output mode register
Register symbol: P3MD
Address: x'36008025
Purpose: This register selects the content output on the port 3 pin.
Bit No. 7 6 543210
Bit name -------P3M
Reset 0 0 000001
Access RRRRRRRR/W
P3M 0: Bus grant signal output (BG)
1: General-purpose input/output port (P30)
Note: When BG is selected in the P3MD register, this control signal is output regardless of the value in the P3DIR
register.
The input/output settings for this general-purpose port are made through the P3DIR register.
15.5.3 Pin Configurations
Table 15-5-1 shows the pin configurations for port 3.
Table 15-5-1 Port 3 Configuration
Port Pin P3n P3M = "1" P3M = "0"
No. P30D = "1" P30D = "0"
Port 3 76 P30 General-purpose output port General-purpose input port BG
Bus grant signal output
[Note]
: When reset (in address/data separate mode or address/data multiplex mode)