Z8018010VSG Datasheet, PDF (18/85 Pages) Zilog, Inc. – Microprocessor Unit

Z80180
Microprocessor Unit
12
(see DC Characteristics on page 21). Several pins are used for different conditions,
depending on the circumstance.
Multiplexed Pin Descriptions
Table 4. Multiplexed Pin Descriptions
Pin
A18/T_OUT
CKA0/DREQ0
CKA1/TEND0
RXS/CTS1
Description
During RESET, this pin is initialized as A18 pin. If either TOC1 or TOC0
bit of the Timer Control Register (TCR) is set to 1, T_OUT function is
selected. If TOC1 and TOC0 are cleared to 0, A18 function is selected.
During RESET, this pin is initialized as CKA0 pin. If either DM1 or SM1
in DMA Mode Register (DMODE) is set to 1, DREQ0 function is always
selected.
During RESET, this pin is initialized as CKA1 pin. If CKA1D bit in ASCI
control register ch1 (CNTLA1) is set to 1, TEND0 function is selected. If
CKA1D bit is set to 0, CKA1 function is selected.
During RESET, this pin is initialized as RXS pin. If CTS1E bit in ASCI
status register ch1 (STAT1) is set to 1, CTS1 function is selected. If
CTS1E bit is set to 0, RXS function is selected.
PS014004-1106
Overview