Pinout and Signal Descriptions
Signal Descriptions
MC68HC912D60A — Rev. 3.1
Technical Data
Freescale Semiconductor
Pinout and Signal Descriptions
51
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 ECLK 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
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).
XIRQ
40
56
Provides a means of requesting asynchronous nonmaskable interrupt
requests after reset initialization
SMODN/BK
GD/TAGHI
15
23
Single-wire background interface pin is dedicated to the background
debug function. During reset, this pin determines special or normal
operating mode. Pin function TAGHI used in instruction tagging. See
PW[3:0]
80, 1–3
112, 1–3
Pulse Width Modulator channel outputs.
SS
70
96
Slave select output for SPI master mode, input for slave mode or master
mode.
SCK
69
95
Serial clock for SPI system.
Table 3-2. MC68HC912D60A Signal Description Summary
Pin Name
Pin Number
Description
80-pin
112-pin