TMPR3901F

Chapter 3 Pins

The following table summarizes the TMPR3901F pins.

NAME

I/O

 

DESCRIPTION

 

 

 

 

I/O

Address bus. When TMPR3901F has bus mastership, outputs the address

A [31:2]

 

to be accessed. When TMPR3901F releases bus mastership, inputs the

 

 

data cache snoop address.

 

 

O

Byte-enable signal. At read and write, indicates which bytes of the data bus

 

 

are accessed by TMPR3901F. The correspondence with the data bus is:

 

 

BE [3]* : D [31:24]

 

BE [3:0]*

 

BE [2]* : D [23:16]

 

 

 

BE [1]* : D [15:8]

 

 

 

 

BE [0]* : D [7:0]

 

 

D [31:0]

I/O

Data bus.

 

 

RD*

O

Read signal. Indicates that a read operation is being executed.

WR*

O

Write signal. Indicates that a write operation is being executed.

LAST*

O

Last signal. Indicates the last data transfer of a bus operation. Please use

 

this signal after sampling for the clock rising edge.

 

 

BSTART*

O

Bus start signal. Asserted for one clock only, at the start of a bus operation.

 

Please use this signal after sampling for the clock rising edge.

 

 

ACK*

I

Acknowledge signal. Used by external circuits to notify TMPR3901F that

 

the bus cycle can be completed.

 

 

 

 

BUSERR*

I

Bus error signal. Used by external circuits to notify TMPR3901F of an error

 

in a read bus operation.

 

 

 

 

 

 

BURST*

O

Burst signal. Indicates that a burst-read operation is being executed.

 

O

Burst size signal. Indicates the number of words to be read in a burst-read

 

 

operation.

 

 

BSTSZ [1:0]

 

BSTSZ[1]

BSTSZ[0]

No. of Word

 

L

L

4

 

 

 

 

L

H

8

 

 

H

L

16

 

 

H

H

32

 

 

 

 

I

Snoop signal. Used by external circuits to instruct snooping of the

SNOOP*

 

TMPR3901F internal data cache. When the SNOOP* signal is asserted, if

 

the address on A[31:2] hits the data in the data cache, TMPR3901F

 

 

 

 

invalidates the data.

 

 

BUSREQ*

I

BUS request signal. Issued by an external bus master to request bus

 

mastership from TMPR3901F.

 

 

 

 

*Active-low signal

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Toshiba TX39 user manual Pins