Pinout and Signal Descriptions
Signal Descriptions
68HC(9)12D60 — Rev 4.0
Advance Information
MOTOROLA
Pinout and Signal Descriptions
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51
3.5.15 Clock generation module test (CGMTST)
The CGMTST pin (PE6) is the output of the clocks tested when CGMTE
bit is set in PEAR register. The PIPOE bit must be cleared for the clocks
to be tested.
Table 3-2. 68HC(9)12D60 Signal Description Summary
Pin Name
Pin Number
Description
80-pin
112-pin
EXTAL
35
47
Crystal driver and external clock input pins. On reset all the device clocks are
derived from the EXTAL input frequency. XTAL is the crystal output.
XTAL
36
48
RESET
34
46
An active low bidirectional control signal, RESET acts as an input to initialize
the MCU to a known start-up state, and an output when COP or clock
monitor causes a reset.
ADDR[7:0]
DATA[7:0]
23–16
31–24
External bus pins share function with general-purpose I/O ports A and B. In
single chip modes, the pins can be used for I/O. In expanded modes, the
pins are used for the external buses.
ADDR[15:8]
DATA[15:8]
48–41
64–57
DBE
25
36
Data bus control and, in expanded mode, enables the drive control of external
buses during external reads.
ECLK
25
36
Inverted E clock used to latch the address.
CAL
25
36
CAL is the output of the Slow Mode programmable clock divider, SLWCLK,
and is used as a calibration reference for functions such as time of day. It is
overridden when DBE function is enabled. It always has a 50% duty cycle.
CGMTST
26
37
Clock generation module test output.
MODB/
IPIPE1,
MODA/
IPIPE0
26, 27
37, 38
State of mode select pins during reset determine the initial operating mode of
the MCU. After reset, MODB and MODA can be configured as instruction
queue tracking signals IPIPE1 and IPIPE0 or as general-purpose I/O pins.
ECLK
28
39
E Clock is the output connection for the external bus clock. ECLK is used as a
timing reference and for address demultiplexing.
LSTRB/
TAGLO
37
53
Low byte strobe (0 = low byte valid), in all modes this pin can be used as I/O.
The low strobe function is the exclusive-NOR of A0 and the internal SZ8
signal. (The SZ8 internal signal indicates the size 16/8 access.) Pin function
TAGLO used in instruction tagging. See
Development Support
.
R/W
38
54
Indicates direction of data on expansion bus. Shares function with general-
purpose I/O. Read/write in expanded modes.
IRQ
39
55
Maskable interrupt request input provides a means of applying asynchronous
interrupt requests to the MCU. Either falling edge-sensitive triggering or
level-sensitive triggering is program selectable (INTCR register).
F
Freescale Semiconductor, Inc.
n
.