Port Ct - NEC V850E/RS1 User Manual

4.3.12 Port CT

Port CT is a 4-bit port for which I/O settings can be controlled in 1-bit units.
(1) Port CT functions
• 4-bit I/O port
• Port input/output specifiable in 1-bit units by port mode register CT (PMCT)
• Port mode/control mode specifiable in 1-bit units by port mode control register CT (PMCCT)
• On-chip pull-up resistor specifiable in 1-bit units by pull-up resistor option register CT (PUCT)
• On-chip pull-down resistor specifiable in 1-bit units by pull-down resistor option register CT
See Table 4-8, "Port Type," on page 170 for alternate functions.
(2) Registers
(a) Port register CT (PCT)
Port register CT (PCT) is an 8-bit register that controls pin level read, output level write. It can be
read and written in 8-bit or 1-bit units.
Symbol
PCT
R/W
Note: PCT7, PCT5, PCT3, PCT2: please set 0 any time.
Remarks: 1. Input mode:
162
Downloaded from Elcodis.com electronic components distributor
(PDCT)
Figure 4-61: Port Register CT (PCT) Format
7 6 5
Note Note
PCT6
0 0
R/W R/W R/W
PCTn Output data control (in output mode) (n = 0, 1, 4, 6)
0 Outputs 0
1 Outputs 1
When port CT (PCT) is read, the pin levels at this time are read. During
write, the data written to PCT is written. This does not affect the input
pins.
Output mode: When port CT (PCT) is read, the value of PCT is read. During write,
the
value is written to PCT and the written value is immediately output.
2. An undefined value (pin input level) is read for the value after reset when PCT is read in
the input mode. When PCT is read in the output mode, 00H (output latch value) is out-
put.
Chapter 4 Port Functions
4 3 2
Note Note
PCT4 PCT1
0 0
R/W R/W R/W R/W
User's Manual U16702EE3V2UD00
1 0 Address After reset
PCT0 FFFFF00AH undefined
R/W