CHAPTER 2 PIN FUNCTIONS
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User’s Manual U15195EJ5V0UD
(5) P40 to P42 (Port 4) … I/O
P40 to P42 function as a 3-bit I/O port in which input or output can be set in 1-bit units.
Besides functioning as an I/O port, in control mode, P40 to P42 operate as serial interface (CSI0) I/O.
Port or control mode can be selected as the operation mode for each bit, specified by the port 4 mode control
register (PMC4).
(a) Port mode
P40 to P42 can be set to input or output in 1-bit units using the port 4 mode register (PM4).
(b) Control mode
P40 to P42 can be set to port or control mode in 1-bit units using PMC4.
(i) SO0 (Serial output) … Output
This pin outputs CSI0 serial transmit data.
(ii) SI0 (Serial input) … Input
This pin inputs CSI0 serial receive data.
(iii) SCK0 (Serial clock) … I/O
This is CSI0 serial clock I/O pin.
(6) PCM0, PCM1 (Port CM) … I/O
PCM0 and PCM1 function as a 2-bit I/O port in which input or output can be set in 1-bit units.
Besides functioning as a port, in control mode, PCM0 and PCM1 operate as wait insertion signal input and
internal system clock output.
Port or control mode can be selected as the operation mode for each bit, specified by the port CM mode
control register (PMCCM).
(a) Port mode
PCM0 and PCM1 can be set to input or output in 1-bit units using the port CM mode register (PMCM).
(b) Control mode
PCM0 and PCM1 can be set to port or control mode in 1-bit units using PMCCM.
(i) WAIT (Wait) … Input
This control signal input pin, which inserts a data wait in a bus cycle, can be input asynchronously to
the CLKOUT signal. Sampling is performed at the falling edge of the CLKOUT signal in the T2 or
TW state of the bus cycle. If the setup or hold time is not secured within the sampling timing, wait
insertion may not be performed.
(ii) CLKOUT (Clock output) … Output
This is an internal system clock output pin. In single-chip mode, output is not performed by the
CLKOUT pin because it is in port mode. To perform CLKOUT output, set this pin to control mode
using the port CM mode control register (PMCCM). This pin performs CLKOUT output, even during
the reset period, in ROMless mode.