MC68HC912D60A MOTOROLA [Motorola, Inc], MC68HC912D60A Datasheet - Page 92

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

Bus Control and Input/Output
Technical Data
92
PIPOE — Pipe Status Signal Output Enable
NECLK — No External E Clock
LSTRE — Low Strobe (LSTRB) Enable
Normal: write once; Special: write anytime EXCEPT the first time.
Read anytime.
Normal single chip: write once; special single chip: write anytime; all
other modes: write never. Read anytime. In peripheral mode, E is an
input and in all other modes, E is an output.
Normal: write once; Special: write anytime EXCEPT the first time.
Read anytime. This bit has no effect in single-chip modes or normal
expanded narrow mode.
LSTRB is used during external writes. After reset in normal expanded
mode, LSTRB is disabled. If needed, it should be enabled before
external writes. External reads do not normally need LSTRB because
all 16 data bits can be driven even if the MCU only needs 8 bits of
data.
In normal expanded narrow mode this pin is reset to an output driving
high allowing the pin to be an output while in and immediately after
reset.
TAGLO is a shared function of the PE3/LSTRB pin. In special
expanded modes with LSTRE set and the BDM tagging on, a zero at
the falling edge of E tags the instruction word low byte being read into
the instruction queue.
Freescale Semiconductor, Inc.
For More Information On This Product,
0 = PE[6:5] are general-purpose I/O (if CGMTE = 1, PE6 is a test
1 = PE[6:5] are outputs and indicate the state of the instruction
0 = PE4 is the external ECLK pin subject to the following limitation:
1 = PE4 is a general-purpose I/O pin.
0 = PE3 is a general-purpose I/O pin.
1 = PE3 is configured as the LSTRB bus-control output, provided
output signal from the CGM module).
queue (only effective in expanded modes).
In single-chip modes, to get an ECLK output signal, it is
necessary to have ESTR = 0 in addition to NECLK = 0.
the MCU is not in single chip or normal expanded narrow
modes.
Bus Control and Input/Output
Go to: www.freescale.com
MC68HC912D60A — Rev 3.0
MOTOROLA