Z80181 Zilog., Z80181 Datasheet - Page 11

• Manufacturer Part Number: Z80181
• Description: SMART ACCESS CONTROLLER (SAC)
• Manufacturer: Zilog.

Zilog
Pin Name
IEI
IEO
/ROMCS
/RAMCS
/RESET
EXTAL
XTAL
PHI
E
TEST
V
V
DS971800500
CC
SS
Pin Number
62
60
61
30
98
94
93
90
86
73
39, 82
18, 40, 59,
63, 92
Input/Output, Tri-State
In, Active 1
Out, Active 1
Out, Active 0
Out, Active 0
In, Active 0
In, Active 1
Out
Out, Active 1
Out, Active 1
Out
Function
Interrupt enable input signal. IEI is used with the IEO to
form a priority daisy chain when there is more than one
interrupt-driven peripheral.
The interrupt enable output signal. In the daisy-chain
interrupt control, IEO controls the interrupt of external
peripherals. IEO is active when IEI is “1” and the CPU is not
servicing an interrupt from the on-chip peripherals.
ROM Chip select. Used to access ROM. Refer to “Func-
tional Description” on chip select signals for further expla-
nation.
RAM Chip Select. Used to access RAM. Refer to “Func-
tional Description” on chip select signals for further expla-
nation.
Reset signal. /RESET signal is used for initializing the MPU
and other devices in the system. It must be kept in the
active state for a period of at least 3 system clock cycles.
Crystal oscillator connecting terminal. A parallel reso-
nant crystal is recommended. If an external clock source
is used as the input to the Z180 Clock Oscillator unit,
supply the clock into this terminal.
Crystal oscillator connecting terminal.
System Clock. Single-phase clock output from Z181
MPU.
Enable Clock. Synchronous Machine cycle clock output
during a bus transaction.
Test pin. Used in the open state.
Power Supply. +5 Volts
Power Supply. 0 Volts
S
MART
A
CCESS
C
ONTROLLER
Z80181
2-11
SAC
™