MC68HC912BD32 Datasheet, PDF (30/292 Pages) Freescale Semiconductor, Inc – Advance Information

Freescale Semiconductor, Inc.
Pinout and Signal Descriptions
Pin Name
CS/SS
SCK
SDO/MOSI
SDI/MISO
TxD
RxD
DIVBYP
Table 5 MC68HC912BD32 Signal Description Summary
Pin Number
Description
68
Slave select output for SPI master mode, input for slave mode or master mode.
67
Serial clock for SPI system.
66
Master out/slave in pin for serial peripheral interface
65
Master in/slave out pin for serial peripheral interface
62
SCI transmit pin
61
SCI receive pin
70
Clock divider bypass
Port Signals
The MC68HC912BD32 incorporates eight ports which are used to
control and access the various device subsystems. When not used for
these purposes, port pins may be used for general-purpose I/O. In
addition to the pins described below, each port consists of a data register
which can be read and written at any time, and, with the exception of port
AD, PE[1:0] and port SBI[1:0], a data direction register which controls
the direction of each pin. After reset all port pins are configured as input.
Port A
Port A pins are used for address and data in expanded modes. The port
data register is not in the address map during expanded and peripheral
mode operation. When it is in the map, port A can be read or written at
anytime.
Register DDRA determines whether each port A pin is an input or output.
DDRA is not in the address map during expanded and peripheral mode
operation. Setting a bit in DDRA makes the corresponding bit in port A
an output; clearing a bit in DDRA makes the corresponding bit in port A
an input. The default reset state of DDRA is all zeroes.
When the PUPA bit in the PUCR register is set, all port A input pins are
pulled-up internally by an active pull-up device. This bit has no effect if
the port is being used in expanded modes as the pull-ups are inactive.
Setting the RDPA bit in register RDRIV causes all port A outputs to have
reduced drive level. RDRIV can be written once after reset. RDRIV is not
MC68HC912BD32 Rev 1.0
Pinout and Signal Descriptions
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10-pins