Hitachi C4K60 Specifications - Page 58

7.5.5. Device Configuration Set [B1h, Sub 03h] Task File Registers Command LBA High LBA Mid LBA Low Device/Head Sector Count Features 7 6 5 4 3 2 1 0 B1h XX XX XX X X X DRV X X X X XX 03h The DEVICE CONFIGURATION SET command allows a device manufacturer or a personal computer system manufacturer to reduce the set of optional commands, modes, or feature sets supported by a device as indicated by a DEVICE CONFIGURATION IDENTIFY command. The DEVICE CONFIGURATION SET command transfers an overlay that modifies some of the bits set in the IDENTIFY DEVICE command response. When the bits in these words are cleared, the device no longer support the indicated command, mode, or feature set. If a bit is set in the overlay transmitted by the device that is not set in the overlay received from a DEVICE CONFIGURATION IDENTIFY command, no action is taken for that bit. The format of the overlay transmitted by the device is described in following table. Table 7.6 DEVICE CONFIGURATION SET command Data Structure Word 0 1 Description Data Structure Revision Word 0 contains the value 0002h. Multiword DMA modes supported bit 15 - 3 0 = Reserved bit 2 1 = Multiword DMA mode 2 and below are supported Bit 2 is cleared to select no support for Multiword DMA mode 2. This bit shall not be cleared if Multiword DMA mode 2 is currently selected. bit 1 1 = Multiword DMA mode 1 and below are supported Bit 1 is cleared to select no support for Multiword DMA mode 1. This bit shall not be cleared if Multiword DMA mode 2 is supported or Multiword DMA mode 1 or 2 is selected. bit 0 1 = Multiword DMA mode 0 is supported Bit 0 shall not be cleared. K6610170 Rev.2 Dec 22, 2004 - 58 -