Registers Controlling Port Function - NEC 78K0/KD1 Series User Manual

4.3 Registers Controlling Port Function

Port functions are controlled by the following three types of registers.
• Port mode registers (PM0, PM1, PM3, PM6, PM7, PM12, PM14)
• Pull-up resistor option registers (PU0, PU1, PU3, PU7, PU12, PU14)
• Input switch control register (ISC)
(1) Port mode registers (PM0, PM1, PM3, PM6, PM7, PM12, and PM14)
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 input sets these registers to FFH.
When port pins are used as alternate-function pins, set the port mode register and output latch as shown in Table
4-4.
Symbol 7 6
PM0 1 1
7 6
PM1 PM17 PM16
7 6
PM3 1 1
7 6
PM6
1 1
7 6
PM7
PM77 PM76
7 6
PM12
1 1
7 6
PM14
1 1
PMmn
0 Output mode (output buffer on)
1 Input mode (output buffer off)
98
CHAPTER 4 PORT FUNCTIONS
Figure 4-19. Format of Port Mode Register
5 4 3
1 1 PM03
5 4 3
PM15 PM14 PM13
5 4 3
1 1 PM33
5 4 3
1 1 PM63
5 4 3
PM75 PM74 PM73
5 4 3
1 1 1
5 4 3
1 1 1
Pmn pin I/O mode selection
(m = 0, 1, 3, 6, 7, 12, 14; n = 0 to 7)
Preliminary User's Manual U16315EJ1V0UD
2 1 0
PM02 PM01 PM00
2 1 0
PM12 PM11 PM10
2 1 0
PM32 PM31 PM30
2 1 0
PM62 PM61 PM60
2 1 0
PM72 PM71 PM70
2 1 0
1 1 PM120
2 1 0
1 1 PM140
Address After reset R/W
FF20H FFH R/W
FF21H FFH R/W
FF23H FFH R/W
FF26H FFH R/W
FF27H FFH R/W
FF2CH FFH R/W
FF2EH FFH R/W