Hitachi HDT725025VLA380 Specifications - Page 259
Write DMA CAh/CBh
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12.46 Write DMA (CAh/CBh) Table 155: Write DMA (CAh/CBh) 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 1 0 1 R 76 CRC UNC V0 Error Register 54 3 2 1 0 0 IDN 0 ABT T0N AMN 0V 0 V 0 0 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 The Write DMA command transfers one or more sectors of data from the host to the device and then the data is written to the disk media. The sectors of data are transferred through the Data Register16 bits at a time. The host initializes a slave-DMA channel prior to issuing the command. Data transfers are qualified by DMARQ and are performed by the slave-DMA channel. The device issues only one interrupt per command to indicate that data transfer has terminated and status is available. If an uncorrectable error occurs, the write will be terminated at the failing sector. Output parameters to the device Sector Count This indicates the number of continuous sectors to be transferred. If zero is specified, then 256 sectors will be transferred. Sector Number This indicates the sector number of the first sector to be transferred. (L = 0)In LBA mode this register contains the LBA bits 0-7. (L = 1) Cylinder High/Low This indicates number of the first sector to be transferred. (L = 0) In LBA mode this register contains the LBA bits 8-15 (Low) and bits 16-23 (High). (L= 1) H This indicates the head number of the first sector to be transferred. (L = 0) In LBA mode this register contains the LBA bits 24-27. (L = 1) R This indicates the retry bit. This bit is ignored. Input parameters from the device Sector Count This indicates the number of requested sectors not transferred. The Sector Count will be zero unless an unrecoverable error occurs. Deskstar T7K500 Hard Disk Drive Specification 245