> I have a project which will provide Wi-Fi  to my old 8052-based design. I
> purchased a TINI module and a 802.11b CF card based on Prism2.5 chipset
and
> got PRISM driver programmer's manual. From previous discussions in this
> newsgroup, I understand that I should set the PRISM MAC into I/O mode by
> writing a value of 1 to bit 0 of the COR(Configuration Option Register).
>
> Because CF card's default mode is memory mode, I think that it is possible
> by connecting -WR, -RD of 8052 to -WE, -OE of CF card and using MOVX
> instruction. But 8052 has no special I/O instruction unlike x86 and I
> leave -IORD, -IOWR of CF card empty. How I can access Prism MAC after
> setting CF card into I/O mode?

You can't - you must use /WR to enable I/O cycles, then /IORD and /IOWR to
talk to the chip. There is also a potential problem that the 8052 cycle time
may be too quick for the WLAN card; it must be stretched to around 500 ns.

The simple way round these problems is to use I/O lines to interface to the
WLAN card (if necessary by adding latches to give extra I/O capability), and
bit-bash them to simulate the bus cycles. This is how our PICmicro PCMCIA
(and CF via an adaptor) interface works.

Jeremy Bentham
Iosoft Ltd.
www.iosoft.co.uk