TMS380C26

NETWORK COMMPROCESSOR

SPWS010A±APRIL 1992±REVISED MARCH 1993

Bit 12: SINTEN Ð System-Interrupt Enable

This bit allows the host processor to enable or disable system interrupt requests from the TMS380C26. The system interrupt request from the TMS380C26 is on the SINTR/SIRQ pin. The following equation shows how the SINTR/SIRQ pin is driven. The table also explains the results of the states.

SINTR/SIRQ = (PSDMAEN * SWHRQ * !SWHLDA) + (SINTEN * SYSTEM_INTERRUPT)

 

 

 

 

SYSTEM

 

PSDMAEN

SWHRQ

SWHLDA

SINTEN

INTERRUPT

RESULT

 

 

 

 

(SIFSTS Reg.)

 

 

 

 

 

 

 

1²

1

1

X

X

Pseudo-DMA is active.

1²

1

0

X

X

The TMS380C26 generated a system

interrupt for a pseudo-DMA.

 

 

 

 

 

1²

0

0

X

X

Not a pseudo-DMA interrupt.

X

X

X

1

1

The TMS380C26 will generate a system

interrupt.

 

 

 

 

 

0

X

X

1

0

The TMS380C26 will not generate a system

interrupt.

 

 

 

 

 

0

X

X

0

X

The TMS380C26 can not generate a system

interrupt.

 

 

 

 

 

 

 

 

 

 

 

² The value on the SHLDA/SBGR pin is ignored.

Bit 13: PEN Ð Adapter Parity Enable

This bit determines whether data transfers within the TMS380C26 are checked for parity.

0= Data transfers are not checked for parity

1= Data transfers are checked for correct odd parity.

Bit 14 Ð 15: NSELOUT (0±1) Ð Network selection outputs.

The values in these bits control the output pins NSELOUT0 and NSELOUT1. These bits can only be modified while the ARESET bit is set.

These bits can be used to software configure a multi-protocol TMS380C26, as follows:

The NSELOUT0 and NSELOUT1 pins should be connected to TEST0 and TEST1 pins respectively (TEST2 should be left unconnected or tied high). NSELOUT0 should be used to select network speed and NSELOUT1 network type, as shown in the table below:

NSELOUT0

NSELOUT1

 

0

0

Reserved

0

1

16 Mbps token ring

1

0

Ethernet (802.3/Blue Book)

1

1

4 Mbps token ring

At power-up these bits are set NSELOUT1 = 1, NSELOUT0 = 0 corresponding to 16 Mbps token ring.

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Texas Instruments TMS380C26 specifications Bit 12 Sinten Ð System-Interrupt Enable, Bit 13 PEN Ð Adapter Parity Enable