II CORE BLOCK: BCU (Bus Control Unit)

A10DRA: Area 10 burst ROM selection (D8) / Areas 10–9 set-up register (0x48126)

A9DRA: Area 9 burst ROM selection (D7) / Areas 10–9 set-up register (0x48126)

Set areas 10 and 9 for use of burst ROM.

Write "1": Burst ROM is used

Write "0": Burst ROM is not used

Read: Valid

When using burst ROM, write "1" to the control bit. The ordinary SRAM interface is selected by writing "0" to the bit.

Area 9 can only be used when the CEFUNC = "00".

At cold start, these bits are set to "0" (burst ROM not used). At hot start, the bits retain their status before being initialized.

RBCLK: BCLK output control (DF) / Bus control register (0x4812E)

Control the bus clock BCLK to enable or disable external output.

Write "1": Fixed at high level

Write "0": Output enabled

Read: Valid

To stop outputting the bus clock from the BCLK pin, write "1" to RBCLK. When the clock output is stopped, the BCLK pin is fixed at high level. The bus clock output from the BCLK pin is enabled by writing "0" to RBCLK. The bus clock output from the BCLK pin also is stopped in the HALT2 and the SLEEP modes.

At cold start, the RBCLK is set to "0" (output enabled). At hot start, RBCLK retains its status before being initialized.

RBST8: Burst mode selection (DD) / Bus control register (0x4812E)

Set the operation mode during a burst read.

Write "1": 8-successive-burst mode

Write "0": 4-successive-burst mode

Read: Valid

The 8-successive-burst mode is selected by writing "1" to RBST8 and the 4-successive-burst mode is selected by writing "0" to RBST8. This setting is valid when areas 10 and 9 are set for burst ROM, and the setting is applied to both areas simultaneously.

At cold start, RBST8 is set to "0" (4-successive-burst mode). At hot start, RBST8 retains its status before being initialized.

REDO: Page mode selection (DC) / Bus control register (0x4812E)

Select the page mode of DRAM.

Write "1": EDO-page mode

Write "0": Fast-page mode

Read: Valid

When using EDO DRAM, write "1" to REDO to select the EDO-page mode.

The contents set here are applied to all of areas 14, 13, 8, and 7 that are set for DRAM.

At cold start, REDO is set to "0" (fast-page mode). At hot start, REDO retains its status before being initialized.

B-II-4-40

EPSON

S1C33L03 FUNCTION PART