III PERIPHERAL BLOCK: INPUT/OUTPUT PORTS

A-1

IOC07–IOC00: P0[7:0] port I/O control (D[7:0]) / P0 port I/O control register (0x402D2)

IOC16–IOC10: P1[6:0] port I/O control (D[6:0]) / P1 port I/O control register (0x402D6)

IOC27–IOC20: P2[7:0] port I/O control (D[7:0]) / P2 port I/O control register (0x402DA)

IOC35–IOC30: P3[5:0] port I/O control (D[5:0]) / P3 port I/O control register (0x402DE)

Directs an I/O port for input or output and indicates the I/O control signal value of the port.

When writing data

Write "1": Output mode

Write "0": Input mode

This I/O control register corresponds bit-for-bit to each I/O port. When an IOC bit is set to "1", the corresponding I/O port is directed for output; if it is set to "0", the I/O port is directed for input.

At cold start, all IOC bits are set to "0" (input). At hot start, IOC retains its state from prior to the initial reset.

If pins P10–P13, P15–P16, P30 and P34 are set for use with peripheral circuits, their pin functions vary depending on the input/output direction control by the IOC1x register.

When reading data

Read "1": I/O control signal (output)

Read "0": I/O control signal (input)

The I/O control signal value for the port pin is read from this register. When I/O port function is selected using the CFEX and CFP registers, the value written to the IOC register is read out as is. When peripheral function is selected, the read value depends on the peripheral circuit status and may not indicate the value written to the IOC register.

However, the read values of the IOC bits for P10–P13, P15–P16, P30, and P34 are the same as the written value even if the peripheral function is selected.

SSIN3: Serial I/F Ch.3 SIN selection (D0) / Port SIO function extension register (0x402D7)

Switches the function of pin P33/#DMAACK1/SIN3.

Write "1":

SIN3

Write "0":

P33/#DMAACK1

Read:

Valid

To use the pin as SIN3, set SSIN3 (D0 / 0x402D7) to "1" and CFP33 (D3 / 0x402DC) to "0". To use the pin as P33 or #DMAACK1, set this bit to "0".

At power-on, this bit is set to "0".

SSOUT3: Serial I/F Ch.3 SOUT selection (D1) / Port SIO function extension register (0x402D7)

Switches the function of pin P16/EXCL5/#DMAEND1/SOUT3.

Write "1":

SOUT3

Write "0":

P16/EXCL5/#DMAEND1

Read:

Valid

To use the pin as SOUT3, set SSOUT3 (D1 / 0x402D7) to "1" and CFP16 (D6 / 0x402D4) to "0". To use the pin as P16, EXCL5, or #DMAEND1, set this bit to "0".

At power-on, this bit is set to "0".

SSCLK3: Serial I/F Ch.3 SCLK selection (D2) / Port SIO function extension register (0x402D7)

Switches the function of pin P15/EXCL4/#DMAEND0/#SCLK3.

Write "1":

#SCLK3

Write "0":

P15/EXCL4/#DMAEND0

Read:

Valid

To use the pin as #SCLK3, set SSCLK3 (D2 / 0x402D7) to "1" and CFP15 (D5 / 0x402D4) to "0". To use the pin as P15, EXCL4, or #DMAEND0, set this bit to "0".

At power-on, this bit is set to "0".

B-III

I/O

S1C33L03 FUNCTION PART

EPSON

B-III-9-9