EB381 Datasheet, PDF (13/16 Pages) Motorola, Inc – Migrating from the MC68HC811E2 to the MC68HC11F1

Freescale Semiconductor, Inc.
Engineering Bulletin
Migrating to the MC68HC11F1
WE
R/W
E
DATA
68HC11F1
CSGPROG
OE
DATA
OE
EPROM
CE
ADDRESS
DATA
OE WE
RAM
CE
ADDRESS
CSGEN
ADDRESS
Figure 9. MC68HC11F1 Non-Multiplexed Bus Example
Memory Map
Example
This example is for connecting an 8- or 16-Kbyte external RAM and a
32-Kbyte external EPROM. See Figure 10.
• Leave internal RAM at default location ($0000–$03FF).
• Leave register block at default location ($1000–$105F).
• Relocate internal EEPROM to address $2E00–$2FFF. This is
done by programming the EE0–EE3 bits in the CONFIG register
($103F) to %0010. You may also need to program the EEON bit
to ensure that the EEPROM is present in the memory map (see
Figure 7).
• CSPROG comes up enabled in expanded mode. You will need to
program the PSIZA and PSIZB bits in the CSCTL register ($105D)
to set an address range. In this example, PSIZA = 0 and
PSIZB = 1 ($8000–$FFFF). The user may also want to clear the
PSTHA and PSTHB bits in the CSSTRH register ($105C) to
ensure no clock stretch is used. Another option with CSPROG is
the priority regarding CSGEN. This can be programmed using the
GCSPR bit in the CSCTL register.
EB381
MOTOROLA
13
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