SH7708 datasheet(309/633 Pages) RENESAS

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I/O Card Interface Timing: Figures 10.47 and 10.48 show the timing for the PCMCIA I/O card

interface.

The I/O card interface is supported only for physical space area 6. Switching between the I/O card

interface and the IC memory card interface is performed according to the accessed address. When

PCMCIA is designated for physical space area 6, the bus access is automatically performed as an

I/O card interface access when a physical address from H'1A000000 to H'1BFFFFFF is accessed.

When accessing a PCMCIA I/O card, the access should be performed using a noncacheable area in

virtual space (P2 or P3 space) or an area specified as noncacheable by the MMU.

When an I/O card interface access is made to a PCMCIA card in little-endian mode, dynamic

sizing of the I/O bus width is possible using the

IOIS16 pin. When a 16-bit bus width is set for

area 6, if the

IOIS16 signal is high during a word-size I/O bus cycle, the I/O port is recognized as

being 8 bits in width. In this case, a data access for only 8 bits is performed in the I/O bus cycle

being executed, followed automatically by a data access for the remaining 8 bits.

Figure 10.49 shows the basic timing for dynamic bus sizing.

In big-endian mode, the

IOIS16 signal is not supported.

In big-endian mode, the

IOIS16 signal should be fixed low.

SH7708 Datasheet(PDF) 309 Page - Renesas Technology Corp