Fujitsu MPB3052AT Manual Do Utilizador

C141-E045-02EN

5 - 73

I) The CRC generator polynomial is :  G (X) = X16 + X12 + X5 + 1.

Note:  Since no bit clock is available, the recommended approach for calculating CRC is
to use a word clock derived from the bus strobe.  The combinational logic shall then be
equivalent to shifting sixteen bits serially through the generator polynominal where DD0 is
shifted in first and DD15 is shifted in last.

Series termination resistors are required at both the host and the device for operation in any of
the Ultra DMA Modes.  The following table describes recommended values for series
termination at the host and the device.

Signal

Host Termination

Device

Termination

DIOR-:HDMARDY-:HSTROBE

33 ohm

82 ohm

DIOW-:STOP

33 ohm

82 ohm

CS0-, CS1-

33 ohm

82 ohm

DA0, DA1, DA2

33 ohm

82 ohm

DMACK-

33 ohm

82 ohm

DD15 through DD0

33 ohm

33 ohm

DMARQ

82 ohm

33 ohm

INTRQ

82 ohm

33 ohm

IORDY:DDMARDY-
:DSTROBE

82 ohm

22 ohm

Note:  Only those signals requiring termination are listed in this table.  If a
signal is not listed, series termination is not required for operation in an Ultra
DMA Mode.  For signals also requiring a pull-up or pull-down resistor at the
host see Figure 5.8.