Fujitsu MHV2040AS Series termination required for Ultra DMA, Dior-Hdmardy-Hstrobe, Diow-Stop

Interface

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 polynomial where DD0 is shifted in first and DD15 is shifted in last.

5.5.6Series termination required for Ultra DMA

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.

Table 5.28 Recommended series termination for Ultra DMA

Signal	Host Termination	Device Termination
DIOR-:HDMARDY-:HSTROBE	22 ohm	82 ohm
DIOW-:STOP	22 ohm	82 ohm
CS0-, CS1-	33 ohm	82 ohm
DA0, DA1, DA2	33 ohm	82 ohm
DMACK-	22 ohm	82 ohm
DD15 through DD0	33 ohm	33 ohm
DMARQ	82 ohm	22 ohm
INTRQ	82 ohm	22 ohm
IORDY:DDMARDY-:DSTROBE	82 ohm	22 ohm
RESET-	33 ohm	82 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.

Vcc

Figure 5.8 Ultra DMA termination with pull-up or pull-down

5-148 C141-E221