Fujitsu MHV2040AH Benutzerhandbuch
Interface
5-148
C141-E217
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.
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.
5.5.6 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.
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.
requiring a pull-up or pull-down resistor at the host see Figure 5.8.
Figure 5.8 Ultra DMA termination with pull-up or pull-down
Vcc