UPD78F0138 NEC, UPD78F0138 Datasheet - Page 280

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

(4) Port mode register 1 (PM1)
280
Remarks 1. f
This register sets port 1 input/output in 1-bit units.
When using the P10/TxD0/SCK10 pin for serial interface data output, clear PM10 to 0 and set the output latch of
P10 to 1.
When using the P11/RxD0/SI10 pin for serial interface data input, set PM11 to 1. The output latch of P11 at this
time may be 0 or 1.
PM1 can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets this register to FFH.
Address: FF21H
Symbol
PM1
2. f
3. k:
4. ×:
5. Figures in parentheses apply to operation at f
PM17
PM1n
XCLK0
X
:
7
0
1
After reset: FFH
: Frequency of base clock selected by the TPS01 and TPS00 bits
X1 input clock oscillation frequency
Value set by the MDL04 to MDL00 bits (k = 8, 9, 10, ..., 31)
Don’t care
Output mode (output buffer on)
Input mode (output buffer off)
PM16
6
Figure 13-5. Format of Port Mode Register 1 (PM1)
CHAPTER 13 SERIAL INTERFACE UART0
PM15
5
R/W
P1n pin I/O mode selection (n = 0 to 7)
User’s Manual U16228EJ2V0UD
PM14
4
PM13
3
X
= 10 MHz
PM12
2
PM11
1
PM10
0