Intel 8XC196NT user manual 87C196CB Supplement, Table A-3. Signal Descriptions Continued

Models: 8XC196NT 87C196CB

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87C196CB Supplement

 

 

Table A-3. Signal Descriptions (Continued)

Name

Type

 

 

 

Description

 

 

 

 

 

BREQ#

O

Bus Request

 

 

 

 

This active-low output signal is asserted during a hold cycle when the bus

 

 

controller has a pending external memory cycle.

 

 

The device can assert BREQ# at the same time as or after it asserts HLDA#.

 

 

Once it is asserted, BREQ# remains asserted until HOLD# is removed.

 

 

You must enable the bus-hold protocol before using this signal.

 

 

BREQ# is multiplexed with P2.3.

 

BUSWIDTH

I

Bus Width

 

 

 

 

The chip configuration register bits, CCR0.1 and CCR1.2, along with the

 

 

BUSWIDTH pin, control the data bus width. When both CCR bits are set, the

 

 

BUSWIDTH signal selects the external data bus width. When only one CCR bit

 

 

is set, the bus width is fixed at either 16 or 8 bits, and the BUSWIDTH signal

 

 

has no effect.

 

 

 

 

CCR0.1

CCR1.2

BUSWIDTH

 

 

 

0

1

N/A

fixed 8-bit data bus

 

 

1

0

N/A

fixed 16-bit data bus

 

 

1

1

high

16-bit data bus

 

 

1

1

low

8-bit data bus

 

 

BUSWIDTH is multiplexed with P5.7.

CLKOUT

O

Clock Output

 

 

 

 

Output of the internal clock generator. The CLKOUT frequency is ½ the

 

 

operating frequency (f). CLKOUT has a 50% duty cycle.

 

 

CLKOUT is multiplexed with P2.7 and PACT#.

COMP1:0

O

Event Processor Array (EPA) Compare Pins

 

 

These signals are the output of the EPA compare-only channels. These pins

 

 

are multiplexed with other signals and may be configured as standard I/O.

 

 

COMP1:0 are multiplexed as follows: COMP0/P6.0/EPA8 and

 

 

COMP1/P6.1/EPA9.

 

 

CPVER

O

Cumulative Program Verification

 

 

 

During slave programming, a high signal indicates that all locations

 

 

programmed correctly, while a low signal indicates that an error occurred during

 

 

one of the programming operations.

 

 

CPVER is multiplexed with P2.6 and HLDA#.

A-6

Page 127
Image 127
Intel 8XC196NT user manual 87C196CB Supplement, Table A-3. Signal Descriptions Continued