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TI486 Microprocessor - Al Kossow's Bitsavers

TI486 Microprocessor - Al Kossow's Bitsavers

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Overview<br />

Table 3-5 shows the state of the <strong>TI486</strong>SLC/E signals when the device is in<br />

suspend mode.<br />

Table 3-5. Signal States During Suspend Mode<br />

SIGNAL SIGNAL STATE DURING SIGNAL STATE DURING HALT<br />

NAME HOLD ACKNOWLEDGE INITIATED SUSPEND MODE<br />

A20M Ignored Ignored<br />

A23-A1 1 1<br />

ADS 1 1<br />

BHE, BLE 0 0<br />

BUSY Ignored Ignored<br />

015-00 Float Float<br />

DIC 1 1<br />

ERROR Ignored Ignored<br />

FLT Input recognized Input recognized<br />

FLUSH Input recognized Input recognized<br />

HLDA 0 0<br />

HOLD Input recognized Input recognized<br />

INTR Latched Input recognized<br />

KEN Ignored Ignored<br />

LOCK 1 1<br />

MilO 0 0<br />

NA Ignored Ignored<br />

NMI Latched Input recognized<br />

PEREQ Ignored Ignored<br />

READY Ignored Ignored<br />

RESET Input recognized Input recognized<br />

SMADS 1 1<br />

SMI Latched Input recognized<br />

SUSP Input recognized Ignored<br />

SUSPA 0 0<br />

W/R 0 0<br />

3.1.2.3 Coprocessor Interface<br />

The data bus, address bus, and bus cycle definition signals, as well as the<br />

coprocessor interface signals (PREQ, BUSY, ERROR), are used to control<br />

communication between the <strong>TI486</strong>SLC/E and a coprocessor. Coprocessor or<br />

ESC opcodes are decoded by the <strong>TI486</strong>SLC/E and the opcode and operands<br />

are then transferred to the coprocessor via liD port accesses to addresses<br />

80 00F8h, 80 OOFCh, or 80 OOFEh. Address 80 00F8h functions as the control<br />

port address and 80 00 FCh and 80 OOFEh are used for operand transfers.<br />

3-15

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