Interface

5.5.6 Series 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 5.15 Recommended series termination for Ultra DMA

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

240 ohm (100 MHz)

 

 

 

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 5.9.

IORDY

DMARQ

 

 

Figure 5.9 Ultra DMA termination with pull-up or pull-down

Configuration of cable

For the configuration of the cable (common use of primary port and secondary port), DMACK signal should not be used in common. It is not recommended to use DIOR-, DIOW- and IORDY signal in common.

5-94

C141-E057-01EN

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Fujitsu MHE2043AT, MHF2043AT manual Series termination required for Ultra DMA, Recommended series termination for Ultra DMA