Z80181 Datasheet, PDF (11/74 Pages) Zilog, Inc. – SMART ACCESS CONTROLLER (SAC™)

Zilog
Z80181
SMART ACCESS CONTROLLER SAC^™
Pin Name
IEI
Pin Number
62
Input/Output, Tri-State
In, Active 1
IEO
60
Out, Active 1
/ROMCS 61
/RAMCS 30
/RESET
98
EXTAL
94
Out, Active 0
Out, Active 0
In, Active 0
In, Active 1
XTAL
PHI
E
TEST
V
CC
V_SS
93
Out
90
Out, Active 1
86
Out, Active 1
73
Out
39, 82
18, 40, 59,
63, 92
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
DS971800500
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