AUTOMOTIVE 87C196KD

Symbol

Name and Function

READY

Ready input to lengthen external memory cycles for interfacing to slow or dynamic memory

or for bus sharing When the external memory is not being used READY has no effect

HSI

Inputs to High Speed Input Unit Four HSI pins are available HSI0 HSI1 HSI2 and HSI3

Two of them (HSI2 and HSI3) are shared with the HSO Unit

HSO

Outputs from High Speed Output Unit Six HSO pins are available HSO0 HSO1 HSO2

HSI3 HSO4 and HSO5 Two of them (HSO4 and HSO5) are shared with the HSI Unit

Port 0

8-bit high impedance input-only port These pins can be used as digital inputs andor as

analog inputs to the on-chip AD converter

Port 1

8-bit quasi-bidirectional IO port

Port 2

8-bit multi-functional port All of its pins are shared with other functions in the 87C196KD

Ports 3 and 4

8-bit bidirectional IO ports with open drain outputs These pins are shared with the

multiplexed addressdata bus

HOLD

Bus Hold input requesting control of the bus

HLDA

Bus Hold acknowledge output indicating release of the bus

BREQ

Bus Request output activated when the bus controller has a pending external memory

cycle

6