This application note demonstrates how the Xicor
X84161/641/129 MPS E2PROM can be interfaced to
the 68HC11 microcontroller family when connected
as shown in Fig. 1. The interface uses the timemultiplexed
address/data bus and two control lines of
the 68HC11 to interface to the MPS E2PROM.
Although the X84161/641/129 requires minimal glue
logic, 3-NAND gates when connected to the 68HC11,
the advantage of the MPS E2PROM as a port-less
serial memory device is still preserved. The 68HC11
assembly code listing for this application note can be
obtained from the Xicor BBS, FaxBack system, or
Xicor's website. The Xicor BBS can be reached at 1-
800-258-8864, or in the (408) area code and
internationally at 1-408-943-0655. Xicor’s BBS will
support up to a 14.4K baud rate modem (8 bits, no
parity, 1 stop bit, and no local echo). The listing can
be found in the MOTOROLA file library. Xicor
application notes are also available through Xicor's
FaxBack system at (408) 954-1627 and from the
WWW using the URL: http://www.xicor.com.