MC68HC912D60A MOTOROLA [Motorola, Inc], MC68HC912D60A Datasheet - Page 93

• Manufacturer Part Number: MC68HC912D60A
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

MC68HC912D60A — Rev 3.0
MOTOROLA
RDWE — Read/Write Enable
CALE — Calibration Reference Enable
DBENE — DBE or Inverted E Clock on Port E[7]
Normal: write once; Special: write anytime EXCEPT the first time.
Read anytime. This bit has no effect in single-chip modes.
R/W is used for external writes. After reset in normal expanded mode,
it is disabled. If needed it should be enabled before any external
writes.
Read and write anytime.
Normal modes: write once. Special modes: write anytime EXCEPT
the first; read anytime.
DBENE controls which signal is output on PE7 when NDBE control bit
is cleared. The inverted ECLK output can be used to latch the address
for demultiplexing. It has the same behaviour as the ECLK, except it
is inverted. Please note that in the case of idle expansion bus, the ‘not
ECLK’ signal could stay high for many cycles.
The DBNE bit has no effect in single chip or peripheral modes and
PE7 is defaulted to the CAL function if the CALE bit is set in the PEAR
register or to an I/O otherwise.
Freescale Semiconductor, Inc.
For More Information On This Product,
0 = PE2 is a general-purpose I/O pin.
1 = PE2 is configured as the R/W pin. In single chip modes, RDWE
0 = Calibration reference is disabled and PE7 is general-purpose
1 = Calibration reference is enabled on PE7 in single chip and
0 = PE7 pin used for DBE external control of data enable on
1 = PE7 pin used for inverted ECLK output in expanded modes
has no effect and PE2 is a general-purpose I/O pin.
I/O in single chip or peripheral modes or if the NDBE bit is set.
peripheral modes or if the NDBE bit is set.
memories in expanded modes when NDBE = 0
when NDBE = 0
Bus Control and Input/Output
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Bus Control and Input/Output
Technical Data
Registers
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