Intel mcs-48 manual Ao-A7, Bo- B7

8286/8287

r-------,		r-------,
	8286		8287
I	I	I	I
	I	~	I
	L-_~~	........ ! L	I

I

Figure 3. Logic Diagrams

Table 1. Pin Description

Pin~e~crlpllon

TTRANSMIT (Input). T is an input control signal ul!ed to control the direction of the transceivers. When HIGH, it configures the transceiver'sBo-B7 as outputs with ArrA7 as inputs. T LOW con· figures Ao-A7 as the outputs with Bo-B7 serVing as the Inputs.

OE	OUTPUT ENABLE (Input). OE Is an input control signal used to enable the appropriate output
	driver (as selected by T) onto its respective bus. This signal Is active LOW.

Ao-A7

~-!!z (8286)

Bo- B7 (8287)

LOCAL BUS DATA PINS (Input/Output). These pins serve to either present data to or accept data from the processor'slocal bus depending upon the state of the T pin.

SYSTEM BUS DATA PINS (Input/Output). These pins serve to either present data to or accept data from the system bus depending upon the state of the T pin.

FUNCTIONAL DESCRIPTION

The 8286 and 8287 transceivers are 8·bittransceivers with high impedance outputs. With T active HIGH and OE active LOW, data at ~he Ao-A7 pins is driven onto the Bo-B7 pins. With T inactive LOW and OE active LOW, data at the Bo-B7 pins is driven onto the Ao-A7 pins. No output low glitchlng will occur whenever the transceivers are entering or leaving the high impedance state.

8-49 AFN 01506A