Hitachi 7K250 Specifications - Page 150
Read DMA Queued C7h
UPC - 000004558972
View all Hitachi 7K250 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 150 highlights
12.16 Read DMA Queued (C7h) Table 76: Read DMA command (C8h/C9h) Command Block Output Registers Register 7 6 5 4 3 2 1 0 Data Feature Sector Count V V V V V V V V Sector Number V V V V V V V V Cylinder Low V V V V V V V V Cylinder High V V V V V V V V Device/Head 1 L 1 D H H H H Command 1 1 0 0 0 1 1 1 76 CRC UNC VV Error Register 54 3 2 1 0 0 IDN 0 ABT T0N AMN 0V 0 V 0 V Command Block Input Registers Register 7 6 5 4 3 2 1 0 Data Error see below Sector Count V V V V V V V V Sector Number V V V V V V V V Cylinder Low V V V V V V V V Cylinder High V V V V V V V V Device/Head - - - - H H H H Status see below Status Register 7 654 3 2 1 0 BSY RDY DF DSC DRQ COR IDX ERR 0 V0V - 0 - V This command executes in a similar manner to a READ DMA command. The device may perform a bus release or it may execute the data transfer without performing a bus release if the data is ready to transfer. If the device performs a bus release, the host shall reselect the device using the SERVICE command. When the data transfer is begun, the device does not perform a bus release until the entire data transfer has been completed. Output parameters to the device Feature The number of sectors to be transferred. A value of 00h indicates that 256 sectors are to be transferred. Sector Count Bits 7 - 3 (Tag) contain the Tag for the command being delivered. Sector Number Starting sector number or LBA address bits 7 - 0. Cylinder High/Low Starting cylinder number or LBA address bits 23 - 8. H Starting head number or LBA address bits 27 - 24 Input parameters from the device on bus release Sector Count Bits 7 - 3 (Tag) contain the Tag of the command being bus released. Bit 2 (REL) is set to one. Bit 1 (I/O) is cleared to zero. Bit 0 (C/D) is cleared to zero. Sector Number, Cylinder High/low, H n/a. SRV Cleared to zero when the device performs a bus release. This bit is set to one when the device is ready to transfer data. Deskstar 7K250 Hard Disk Drive Specification 136