IBM DTCA-24090 Hard Drive Specifications - Page 125

Read Long 22h/23h

Get IBM DTCA-24090 - Travelstar 4.1 GB Hard Drive PDF manuals and user guides View all IBM DTCA-24090 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 125 highlights

12.13 Read Long (22h/23h) Command Block Output Registers Register 76543210 Data Feature Sector Count 0 0 0 0 0 0 0 1 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 1L1DHHHH Command 0010001R Command Block Input Registers Register 76543210 Data Error ...See Below... Sector Count 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 HHHH Status ...See Below... Error Register 76543210 CRC UNC 0 IDN 0 ABT T0N AMN 000V0V0V Status Register 76543210 BSY RDY DF DSC DRQ COR IDX ERR 0V0V 0 V Figure 73. Read Long Command (22h/23h) The Read Long command reads the designated one sector of data and the ECC bytes from the disk media, then transfers the data and ECC bytes from the device to the host. After 512 bytes of data have been transferred, the device will keep setting D R Q = 1 to indicate that the device is ready to transfer the ECC bytes to the host. The data is transferred 16 bits at a time, and the ECC bytes are transferred 8 bits at a time. The number of ECC bytes are 4 or 28 according to the setting of Set Feature option. The default setting is 4 bytes of ECC data. The command makes a single attempt to read the data and does not check the data using ECC. Whatever is read is returned to the host. Output Parameters To The Device Sector Count The number of continuous sectors to be transferred. The Sector Count must be set to one. Sector Number The sector number of the sector to be transferred. ( L = 0 ) In LBA mode, this register contains LBA bits 0 - 7. ( L = 1 ) Cylinder High/Low The cylinder number of the sector to be transferred. ( L = 0 ) In LBA mode, this register contains LBA bits 8 - 15 (Low), 16 - 23 (High). ( L = 1 ) Command Descriptions 117

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
12.13
Read Long (22h/23h)
Command Block Output Registers
Command Block Input Registers
Register
76543210
Register
76543210
Data
Data
Feature
Error
...See Below...
Sector Count
00000001
Sector Count
V
Sector Number
VVVVVVVV
Sector Number
VVVVVVVV
Cylinder Low
VVVVVVVV
Cylinder Low
VVVVVVVV
Cylinder High
VVVVVVVV
Cylinder High
VVVVVVVV
Device/Head
1L1DHHHH
Device/Head
HHHH
Command
0010001R
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
0
0
0
V
0
V
0
V
0
V
0
V
0
V
Figure 73. Read Long Command (22h/23h)
The Read Long command reads the designated one sector of data and the ECC bytes from the disk media,
then transfers the data and ECC bytes from the device to the host.
After 512 bytes of data have been transferred, the device will keep setting DRQ=1 to indicate that the device
is ready to transfer the ECC bytes to the host.
The data is transferred 16 bits at a time, and the ECC bytes
are transferred 8 bits at a time.
The number of ECC bytes are 4 or 28 according to the setting of Set Feature
option.
The default setting is 4 bytes of ECC data.
The command makes a single attempt to read the data and does not check the data using ECC. Whatever is
read is returned to the host.
Output Parameters To The Device
Sector Count
The number of continuous sectors to be transferred.
The Sector Count must be set
to one.
Sector Number
The sector number of the sector to be transferred. (L=0)
In LBA mode, this register contains LBA bits
0 - 7. (L=1)
Cylinder High/Low
The cylinder number of the sector to be transferred. (L=0)
In LBA mode, this register contains LBA bits
8 - 15 (Low), 16 - 23 (High). (L=1)
Command Descriptions
117