M68HC16 Z SERIES
OVERVIEW
USER’S MANUAL
3-15
Table 3-5 M68HC16 Z-Series Signal Function
Mnemonic
Signal Name
Function
ADDR[19:0]
Address Bus
20-bit address bus used by CPU16
AN[7:0]
ADC Analog Input
Inputs to ADC multiplexer
AS
Address Strobe
Indicates that a valid address is on the address bus
AVEC
Autovector
Requests an automatic vector during interrupt acknowledge
BERR
Bus Error
Indicates that a bus error has occurred
BG
Bus Grant
Indicates that the MCU has relinquished the bus
BGACK
Bus Grant
Acknowledge
Indicates that an external device has assumed bus mastership
BKPT
Breakpoint
Signals a hardware breakpoint to the CPU
BR
Bus Request
Indicates that an external device requires bus mastership
CLKOUT
System Clockout
System clock output
CS[10:0]
Chip-Selects
Select external devices at programmed addresses
CSBOOT
Boot Chip Select
Chip select for external boot start-up ROM
DATA[15:0]
Data Bus
16-bit data bus
DS
Data Strobe
During a read cycle, indicates that an external device should
place valid data on the data bus. During a write cycle, indicates
that valid data is on the data bus.
DSACK[1:0]
Data and Size
Acknowledge
Provide asynchronous data transfers and dynamic bus sizing
DSI, DSO,
DSCLK
Development Serial In,
Out, Clock
Serial I/O and clock for background debug mode
EXTAL, XTAL
Crystal Oscillator
Connections for clock synthesizer circuit reference a crystal or
an external oscillator can be used
FC[2:0]
Function Codes
Identify processor state and current address space
FREEZE
Freeze
Indicates that the CPU has entered background mode
HALT
Halt
Suspend external bus activity
IRQ[7:1]
Interrupt Request Level
Provides an interrupt priority level to the CPU
IPIPE[1:0]
Instruction Pipeline
Indicate instruction pipeline activity
MISO
Master In Slave Out
Serial input to QSPI in master mode; serial output from QSPI in
slave mode
MISO
1
Master In Slave Out
Serial input to SPI in master mode; serial output from SPI in
slave mode
MODCLK
Clock Mode Select
Selects the source and type of system clock
MOSI
Master Out Slave In
Serial output from QSPI in master mode; serial input to QSPI in
slave mode
MOSI
Master Out Slave In
Serial output from SPI in master mode; serial input to SPI in
slave mode
PADA[7:0]
Port ADA
ADC digital input port signals
PAI
Pulse Accumulator Input
Input to the GPT pulse accumulator
PCLK
Auxiliary Timer Clock
GPT external clock input
PC[6:0]
Port C
Port C digital output port signals
PCS[3:0]
Peripheral Chip Select
QSPI peripheral chip-selects
PE[7:0]
Port E
Port E digital I/O port signals
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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