Typewriter User Manual

2- 14 MC68340 USER’S MANUAL MOTOROLA
Table 2-5. Signal Summary
Signal Name Mnemonic Input/Output Active State Three-State
Address Bus A23–A0 Out — Yes
Address Bus Port A7–A0/
Interrupt Acknowledge
A31–A24 Out/I/O/Out —/—/Low Yes
Data Bus D15–D0 I/O — Yes
Function Codes FC3–FC0 Out — Yes
Chip Select 3/Interrupt Request
Level/Port B4, B2, B1
CS3–CS1 Out/In/I/O Low/Low/— No
Chip Select 0/Autovector CS0 Out/In Low/Low No
Bus Request BR In Low —
Bus Grant BG Out Low No
Bus Grant Acknowledge BGACK In Low —
Data and Size Acknowledge DSACK1,
DSACK0
In Low —
Read-Modify-Write Cycle RMC Out Low Yes
Address Strobe AS Out Low Yes
Data Strobe DS Out Low Yes
Size SIZ1, SIZ0 Out — Yes
Read/Write R/W Out High/Low Yes
Interrupt Request Level/
Port B7, B6, B5, B3
IRQ7, IRQ6,
IRQ5, IRQ3
In/I/O Low/— —
Reset RESET I/O Low No
Halt HALT I/O Low No
Bus Error BERR In Low —
System Clock CLKOUT Out — No
Crystal Oscillator EXTAL, XTAL In, Out — —
External Filter Capacitor XFC In — —
Clock Mode Select/Port B0 MODCK In/I/O —/— —
Instruction Fetch/
Development Serial In
IFETCH/DSI Out/In Low/— No/—
Instruction Pipe/
Development Serial Out
IPIPE/DSO Out/Out Low/— No/—
Breakpoint/
Development Serial Clock
BKPT/DSCLK In/In Low/— —/—
Freeze FREEZE Out High No
Receive Data RxDA, RxDB In — —
Frees
cale Semiconductor,
I
Freescale Semiconductor, Inc.
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