Datasheet

78K0/Ix2 CHAPTER 8 8-BIT TIMER/EVENT COUNTER 51
R01UH0010EJ0500 Rev.5.00 328
Feb 28, 2012
(4) Port mode registers 0 and 3 (PM0, PM3)
These registers set ports 0 and 3 input/output in 1-bit units.
PM0 and PM3 can be set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation sets these registers to FFH.
78K0/IY2
When using the <TI51>/P34/TOX11/<TOH1>/INTP4 pin for timer input, set PM34 to 1
. The output latch of P34 at this
time may be 0 or 1.
78K0/IA2, 78K0/IB2 (32 pins)
When using the <TI51>/P34/TOX11/<TOH1>/INTP4 and <TI51>/P00/TI000/<TOH1>/INTP0 pins for timer input, set
PM34 and PM00 to 1. The output latches of P34 and P00 at this time may be 0 or 1.
78K0/IB2 (30 pins)
When using the TI51/P30/TOH1/INTP1pin for timer input, set PM30 to 1
. The output latch of P30 at this time may be
0 or 1.
Figure 8-7. Format of Port Mode Register 0 (PM0)
Address: FF20H After reset: FFH R/W
Symbol 7 6 5 4 3 2 1 0
PM0 1 1 1 1 1 1 1 PM00
PM00 P00 pin I/O mode selection
0 Output mode (output buffer on)
1 Input mode (output buffer off)
Remark The figure shown above presents the format of port mode register 0 of the 78K0/IA2.
Figure 8-8. Format of Port Mode Register 3 (PM3)
Address: FF23H After reset: FFH R/W
Symbol 7 6 5 4 3 2 1 0
PM3 PM37 PM36 PM35 PM34 PM33 PM32 PM31 PM30
PM3n P3n pin I/O mode selection (n = 0 to 7)
0 Output mode (output buffer on)
1 Input mode (output buffer off)
Remark The figure shown above presents the format of port mode register 3 of the 78K0/IB2 (30 pins).
For the format of port mode register 3 of other products, refer to (1) Port mode registers
(PMxx) in 4.3 Registers Controlling Port Function.