Hitachi HDS728080PLAT20 Specifications - Page 153

Read DMA Ext 25h

Page 153 highlights

12.16 Read DMA Ext (25h) Table 98: Read DMA Ext Command (25h) Command Block Output Registers Register 7 6 5 4 3 2 1 0 Data Low Data High Current Feature Previous Sector Count Current Previous V V V V V V V V V V V V V V V V Sector Number Current Previous V V V V V V V V V V V V V V V V Cylinder Current Low Previous V V V V V V V V V V V V V V V V Cylinder Current V V V V V V V V High Previous V V V V V V V V Device/Head 1 1 1 0 - - - - Command 0 0 1 0 0 1 0 1 76 CRC UNC V Vs 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 Low Data High Error see below Sector Count HOB=0 HOB=1 Sector Number HOB=0 HOB=1 Cylinder HOB=0 Low HOB=1 Cylinder HOB=0 High HOB=1 Device/Head Status V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V See below ... Status Register 7 654 3 2 1 0 BSY RDY DF DSC DRQ COR IDX ERR 0 V0V - 0 - V The Read DMA command reads one or more sectors of data from disk media, then transfers the data from the device to the host. The sectors are transferred through the Data Register 16 bits at a time. The host initializes a slave-DMA channel prior to issuing the command. The 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 read will be terminated at the failing sector. Output parameters to the device Sector Count Current The number of sectors to be transferred low order, bits (7:0). Sector Count Previous The number of sectors to be transferred high order, bits (15:8). If 0000h in the Sector Count register is specified, then 65,536 sectors will be transferred. Sector Number Current LBA (7:0) Sector Number Previous LBA (31:24) Cylinder Low Current LBA (15:8) Cylinder Low Previous LBA (39:32) Deskstar 7K80 Hard Disk Drive Specification 149

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Deskstar 7K80 Hard Disk Drive Specification
149
12.16
Read DMA Ext (25h)
Table 98: Read DMA Ext Command (25h)
The Read DMA command reads one or more sectors of data from disk media, then transfers the data from the
device to the host.
The sectors are transferred through the Data Register 16 bits at a time.
The host initializes a slave-DMA channel prior to issuing the command. The data transfers are qualified by
DMARQ and are performed by the slave-DMA channel. The device issues only one interrupt per command to indi-
cate that data transfer has terminated and status is available.
If an uncorrectable error occurs, the read will be terminated at the failing sector.
Output parameters to the device
Sector Count Current
The number of sectors to be transferred low order, bits (7:0).
Sector Count Previous
The number of sectors to be transferred high order, bits (15:8).
If 0000h in the
Sector Count register is specified, then 65,536 sectors will be transferred.
Sector Number Current
LBA (7:0)
Sector Number Previous
LBA (31:24)
Cylinder Low Current
LBA (15:8)
Cylinder Low Previous
LBA (39:32)
Command Block Output Registers
Command Block Input Registers
Register
7 6 5 4 3 2 1 0
Register
7 6 5 4 3 2 1 0
Data Low
- - - - - - - -
Data Low
- - - - - - - -
Data High
- - - - - - - -
Data High
- - - - - - - -
Feature
Current
- - - - - - - -
Error
see below
Previous
- - - - - - - -
Sector
Count
Current
V V V V V V V V
Sector
Count
HOB=0
- - - - - - - -
Previous
V V V V V V V V
HOB=1
- - - - - - - -
Sector
Number
Current
V V V V V V V V
Sector
Number
HOB=0
V V V V V V V V
Previous
V V V V V V V V
HOB=1
V V V V V V V V
Cylinder
Low
Current
V V V V V V V V
Cylinder
Low
HOB=0
V V V V V V V V
Previous
V V V V V V V V
HOB=1
V V V V V V V V
Cylinder
High
Current
V V V V V V V V
Cylinder
High
HOB=0
V V V V V V V V
Previous
V V V V V V V V
HOB=1
V V V V V V V V
Device/Head
1 1 1 0 - - - -
Device/Head
- - - - - - - -
Command
0 0 1 0 0 1 0 1
Status
See below ...
Error Register
Status Register
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
CRC UNC 0 IDN 0 ABT T0N AMN
BSY RDY DF DSC DRQ COR IDX ERR
V
Vs
0
V
0
V
0
0
0
V
0
V
-
0
-
V