Hitachi 7K250 Specifications - Page 61
for DD0 through DD15, DMARQ, INTRQ, for CS0-, CS1-, DA0, DA1, DA2, DIOR-, DIOW-, DMACK, for IORDY
UPC - 000004558972
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DMACKThis signal shall be used by the host in response to DMARQ to either acknowledge that data has been accepted, or that data is available. This signal is internally pulled up to 5 Volt through a 15kΩ resistor with a resistor tolerance value of -50% to +100%. DMARQ This signal is used for DMA data transfers between the host and drive. It shall be asserted by the drive when it is ready to transfer data to or from the host. The direction of data transfer is controlled by DIOR- and DIOWsignals. This signal is used in a handshake mode with DMACK-. This signal is a 3-state line with 24 mA sink capability and internally pulled down to GND through a 10 kΩ resistor. HDMARDY- (Ultra DMA) This signal is used only for Ultra DMA data transfers between host and drive. The signal HDMARDY- is a flow control signal for Ultra DMA data in bursts. This signal is held asserted by the host to indicate to the device that the host is ready to receive Ultra DMA data in transfers. The host may negate HDMARDY- to pause an Ultra DMA data in transfer. HSTROBE (Ultra DMA) This signal is used only for Ultra DMA data transfers between host and drive. The signal HSTROBE is the data out strobe signal from the host for an Ultra DMA data out transfer. Both the rising and falling edge of HSTROBE latch the data from DD (15:0) into the device. The host may stop toggling HSTROBE to pause an Ultra DMA data out transfer. STOP (Ultra DMA) This signal is used only for Ultra DMA data transfers between host and drive. The STOP signal shall be asserted by the host prior to initiation of an Ultra DMA burst. A STOP shall be negated by the host before data is transferred in an Ultra DMA burst. Assertion of STOP by the host during or after data transfer in an Ultra DMA mode signals the termination of the burst. DDMARDY- (Ultra DMA) This signal is used only for Ultra DMA data transfers between host and drive. The signal DDMARDY- is a flow control signal for Ultra DMA data out bursts. This signal is held asserted by the device to indicate to the host that the device is ready to receive Ultra DMA data out transfers. The device may negate DDMARDY- to pause an Ultra DMA data out transfer. DSTROBE (Ultra DMA) This signal is used only for Ultra DMA data transfers between host and drive. The signal DSTROBE is the data in strobe signal from the device for an Ultra DMA data in transfer. Both the rising and the falling edge of DSTROBE latch the data from DD (15:0) into the host. The device may stop toggling DSTROBE to pause an Ultra DMA data in transfer. Device termination The termination resistors on the device side are implemented on the drive side as follows: • 33 Ω for DD0 through DD15, DMARQ, INTRQ • 82 Ω for CS0-, CS1-, DA0, DA1, DA2, DIOR-, DIOW-, DMACK• 22 Ω for IORDY Deskstar 7K250 Hard Disk Drive Specification 47