PC87570-ICCSLASHVUL datasheet(59/168 Pages) NSC

59 / 168 page

Host Bus Interface (HBI)

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may load it with an address and lock it against any fur-

ther writes. This guarantees that the address does not

change due to a software bug.

The initiation key contains a series of 32 values. The

first 30 values match 30 values that the LFSR Register

generates, starting from 6Ah. To avoid conflict with oth-

er devices that use PnP ISA Specification 1.0a, the last

two values must be 00h.

The values in the initiation key, in hexadecimal notation,

reading from left to right and top to bottom, must be:

6A, B5, DA, ED, F6, FB, 7D, BE,

DF, 6F, 37, 1B, 0D, 86, C3, 61,

B0, 58, 2C, 16, 8B, 45, A2, D1,

E8, 74, 3A, 9D, CE, E7, 00, 00.

If the sequence is successfully completed, the PC87570

enables the configuration base address update.

If any of the write operations in this sequence do not

match, the enable process is stopped and the hardware

resets the LFSR Register to its initial value (step 1). The

following two write operations define the FFD Configu-

ration Register Base Address, SBAH and SBAL, in that

order.

Shift Direction

Shift Clock

Preset Control

Preset Value = 6Ah

Key Output

Figure 5-6. Initiation Key Generation (LFSR)

I/O Write

Reset or

Error

Detection

Reset

Wait for key

Is this

the ﬁrst value

of the key?

Save the address

Wait for the

next value of

the key

Is this

the next value

in the key?

Is this

the last value

in the key?

SBAH

update mode

Update SBAH with

the data

SBAL

update mode

Update SBAL with

the data

Index and Data

Registers are

accessible

Reset signal inactive

I/O write to the saved

Any

End

Any other I/O

transaction

Any other I/O

transaction

Any other I/O

transaction

Yes

other

I/O

transaction

Figure 5-7. Initialization Sequence

address

I/O Write to

0279h, 03F0h or 03BDh

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