Fujitsu MB90460 Series Hardware Manual page 208

■ Block Diagram of Port 4 Pins
Figure 9.7-1 is a block diagram of port 4 pins.
Port data register (PDR)
PDR read
PDR write
Port data direction register (DDR)
DDR write
DDR read
When the resource output enable bit is set, the port is forcibly caused to function as resource output pins
regardless of the value in the DDR4 register.
■ Port 4 Registers
Port 4 registers are PDR4 and DDR4. The bits making up each register correspond to the port 4 pins on a
one-to-one basis. Table 9.7-2 lists the port 4 pins and their corresponding register bits.
Table 9.7-2 Port 4 Pins and their Corresponding Register Bits
Port
PDR4, DDR4
Port 4
Corresponding pin
Figure 9.7-1 Block Diagram of Port 4 Pins
Output latch
Direction latch
Register bits and corresponding port pins
bit7 bit6
– P46
Resource output Resource input
Resource output enable
Standby control (SPL = 1)
bit5 bit4 bit3
P45 P44 P43
CHAPTER 9 I/O PORT
Pin
bit2 bit1 bit0
P42 P41 P40
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