SH7708 datasheet(222/633 Pages) RENESAS

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Bit 2n + 1: AnSZ1

Bit 2n: AnSZ0

Bit 0: PORTEN

Description

Reserved (not settable)

Byte (8-bit) size

Word (16-bit) size

Longword (32-bit) size

(Initial value)

Reserved (not settable)

Byte (8-bit) size

Word (16-bit) size

Reserved (not settable)

Bit 0—Port Function Enable (PORTEN): Designates whether to use the D23–D16 pins as an 8-bit

port. When using this function set the bus widths to word or byte in all areas.

Bit 0: PORTEN

Description

D23–D16 are not used as a port.

(Initial value)

D23–D16 are used as a port.

10.2.3

Wait State Control Register 1 (WCR1)

Wait state control register 1 (WCR1) is a 16-bit read/write register that specifies the number of

idle (wait) state cycles inserted for each area. For some memories, the drive of the data bus may

not be turned off quickly even when the read signal from the external device is turned off. This

can result in conflicts between data buses when consecutive memory accesses are to different

memories or when a write immediately follows a memory read. The SH7708 Series automatically

inserts idle states equal to the number set in WCR1 in those cases.

WCR1 is initialized to H'3FFF by a power-on reset. It is not initialized by a manual reset or in

standby mode, but retains its contents.

SH7708 データシート(PDF) 222 Page - Renesas Technology Corp