SH7763 Datasheet, PDF (629/2026 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC Engine Family SH-4A Series

Section 13 PCI Controller (PCIC)
To prevent a device that does not execute REQ negation and FRAME assertion simultaneously
(figure 13.27) from being a bus master, preventive measure 1 or 2 below should be taken.
1. Use pseudo-round-robin mode.
Pseudo-round-robin mode should be set (BMAM bit in PCICR = 1) as the PCI bus arbitration
scheme.
2. Assign the lowest priority level to the relevant device.
When there is only one device that does not execute REQ negation and FRAME assertion
simultaneously, the device should be connected to the REQn and GNTn with the lowest
priority.
However, if none of the external devices connected to the PCI has such negation/assertion timing
or if none of the external devices with such negation/assertion timing can be a bus master, the
above preventive measures are not required.
Rev. 1.00 Oct. 01, 2007 Page 563 of 1956
REJ09B0256-0100