Intel 80386

APPENDIX B
80387 EMULATOR PAL DESCRIPTION
This section describes the PAL equations for the Math Control PAL in the 80386 emulator
circuit. These equations are listed in Figure B-1.
The primary function of the PAL
is to decode the 80386 outputs and generate 80287 inputs.
The CLK16D#, DVALID#, and AVALID# signals provide for the correct timing of the
outputs. The TP2 input provides the ability to force the PAL outputs to the high impedance
state. For normal operation, TP2
is pulled high.
PAL16LBB PAL DESIGN SPECIFICATION
386/100 27 February 1986 ED JACKS
PAL: MATH CYCle MATHCYC
INTeL Corporation
IRDY A31 LRESET lADS MIO IRD IAVALID IDVALID ICLK16 GND
TP2 ICLK16D IREADYO IDVALIDD IAVALIDD NC IIORDD IIOWCD IREADYOD VCC
IF (TP2) AVALIDD • ADS • RDY • ILRESET • CLK16 • IAVALID
+ IRDY • A31 • IMIO • ILRESET • AVALID
+ A31 • IMIO • ILRESET • AVALID • DVALID
+ ADS • ILRESET • CLK16 • IAVALID • DVALID
+ ILRESET • ICLK16 • AVALID
IF (TP2) DVALIDD • ILRESET • CLK16 • AVALID • DVALID
+ IRDY • ILRESET • DVALID
+ ADS • ILRESET • CLK16 • IDVALID
+ ILRESET • ICLK16 • DVALID
IF (TP2) IORDD • IRDY • A31 • IMIO • IRD • AVALID • DVALID
+ A31 • IMIO • ICLK16 • RD • AVALID • DVALID
IF (TP2) IOWCD • IRDY • A31 • IMIO • RD • AVALID • DVALID
+ A31 • IMIO • ICLK16 • IRD • AVALID • DVALID
IF (TP2) READYOD • A31 • IMIO • ICLK16 • READYO • AVALID • DVALID
+ IRDY • A31 • IMIO • CLK16 • AVALID • DVALID
CLK16D
• ILRESET • ICLK16
Figure 8-1. 80387 Emulator PAL Equations
8-1