Datasheet

78K0/Ix2 CHAPTER 4 PORT FUNCTIONS
R01UH0010EJ0500 Rev.5.00 134
Feb 28, 2012
4.3 Registers Controlling Port Function
Port functions are controlled by the following eight types of registers.
Port mode registers (PMxx)
Port registers (Pxx)
Pull-up resistor option registers (PUxx)
Port input mode register 6 (PIM6)
Note 1
Port output mode register 6 (POM6)
Note 1
Reset pin mode register (RSTMASK)
A/D port configuration registers 0, 1
Note 2
(ADPC0, ADPC1
Note 2
)
Port alternate switch control register (MUXSEL)
Notes 1. 78K0/IA2, 78K0/IB2 only
2. 78K0/IB2 only
(1) Port mode registers (PMxx)
These registers specify input or output mode for the port in 1-bit units.
These registers can be set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation sets these registers to FFH.
When port pins are used as alternate-function pins, set the port mode register by referencing 4.5 Settings of Port
Mode Register and Output Latch When Using Alternate Function.
Figure 4-25. Format of Port Mode Register (78K0/IY2)
7Symbol 6 5 4 3 2 1 0 Address After reset R/W
1
PM2
1 PM25
Note
PM24
Note
PM23
Note
1 PM21
Note
PM20
Note
FF22H FFH R/W
1
PM3
1 1 PM34 PM33 PM32 PM31 1
FF23H FFH R/W
PMmn
Pmn pin I/O mode selection
(m = 2, 3; n = 0 to 5)
0 Output mode (output buffer on)
1 Input mode (output buffer off)
Note If this pin is set as an analog input by using the ADPC0 register, be sure to set it to input mode.
Caution Be sure to set bits 2, 6, 7 of PM2, bits 0, 5 to 7 of PM3 to 1.