r8a77850anbg Renesas Electronics Corporation., r8a77850anbg Datasheet - Page 692

Manufacturer Part Number

r8a77850anbg

Renesas 32-bit Risc Microcomputer Superh? Risc Engine Family

Manufacturer

Renesas Electronics Corporation.

Manufacturer

BOSTOCK HK LIMITED

Part Number:

r8a77850anbgV

Manufacturer:

Renesas Electronics America

13. PCI Controller (PCIC)

By writing 1 to the SC bit in PCICMD, a wait (stepping) of one clock can be inserted when the

PCIC is driving the AD bus. As a result, the PCIC drives the AD bus with 2 clocks. This function

can be used when the PCI bus load is heavy and the AD bus does not achieve the stipulated logic

level in one clock.

It is recommended to use this function when the PCIC issues configuration transfers in host mode.

Figure 13.27 shows an example of a burst memory write cycle with address stepping. Figure 13.28

shows an example of a target burst read cycle with address stepping.

Rev.1.00 Jan. 10, 2008 Page 662 of 1658

REJ09B0261-0100

Address/Data Stepping Timing

Figure 13.27 Master Write Cycle in Host Mode (Burst, with Stepping)

Addr: PCI space address

DPn: nth data parity

AP: Address parity

Com: Command

BEn: nth data byte enable