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10.3.4 Series resistance
Each signal has its own series resistance.
SIGNAL  | SERIAL RESISTANCE VALUE  | 
82Ω  | |
  | |
HSTROBE  | 
  | 
  | 
  | 
82Ω  | |
STOP  | 
  | 
  | 
  | 
82Ω  | |
DA0,DA1,DA2  | 82Ω  | 
82Ω  | |
DMARQ  | 22Ω  | 
INTRQ  | 22Ω  | 
IORDY  | 22Ω  | 
  | |
DSTROBE  | 
  | 
  | 
  | 
DD0~DD15  | 33Ω  | 
10.3.5 Signal Description
SIGNAL | DIR. | PIN | DESCRIPTION | 
- RESET | O (*1)  | 1  | Reset signal from the host system; It shall be active low when system is  | 
  | 
  | 
  | |
DD 15- 0  | I/O  | 18- 3  | 16 bit bi- directional data bus between the host system and the drive. All 16 bits  | 
  | 
  | 
  | are used for data transfer in the data register. The lower 8 bits, HD0- HD7, are  | 
  | 
  | 
  | used for the other register and ECC access.  | 
KEY | N/C  | 20  | Pin position 20 has no connection pin, clipped on the drive and plugged on the  | 
  | 
  | 
  | cable in order to ensure correct orientation of the cable and to avoid wrong  | 
  | 
  | 
  | insertion.  | 
DMARQ | I  | 21  | DMA request signal is set by the drive to indicate that the DMA data transfer is  | 
  | 
  | 
  | ready. The direction of the data transfer is controlled by write/read strobe signal  | 
  | 
  | 
  | (HOST IOW or HOST IOR). This signal is used on a hand shake manner with -  | 
  | 
  | 
  | DMACK.  | 
- DIOW  | O  | 23  | Write strobe. The rising clocks data from the host data bus, HD0 through HD15 to  | 
STOP | 
  | 
  | a register or data register of the drive.  | 
  | 
  | 
  | Stop signal used by the host after the completion of Ultra DMA Burst.  | 
- DIOR | O  | 25  | Read strobe. When active low, this signal enables data from a register or the data  | 
  | 
  | 
  | of the drive onto the host data bus, HD0 through HD15. The rising edge of  | 
  | 
  | 
  | |
 | 
  | 
  | This signal is for reporting the drive that the host system is ready to accept Ultra  | 
  | 
  | 
  | DMA data.  | 
HSTROBE | 
  | 
  | Strobe. HSTROBE indicates that the host transfers ULTRA DMA data. The rising  | 
  | 
  | 
  | edge and the falling edge of HSTROBE enable the drive to latch the data.  | 
IORDY  | I  | 27  | IORDY reports host that the BUS is available.  | 
  | 
  | ||
  | 
  | 
  | data.  | 
DSTROBE | 
  | 
  | Strobe. DSTROBE is asserted to indicate that the drive transfers Ultra DMA data.  | 
  | 
  | 
  | The rising edge and falling edge of DSTROBE enable the host to latch the data.  | 
Copyright © 2000 Toshiba corporation. All rights reserved.
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