5.2 Logical Interface
(10) Command register (X’1F7’)
The Command register contains a command code being sent to the device. After this register is written, the command execution starts immediately.
Table 5.3 lists the executable commands and their command codes. This table also lists the necessary parameters for each command which are written to certain registers before the Command register is written.
5.2.3 Control block registers
(1) Alternate Status register (X’3F6’)
The Alternate Status register contains the same information as the Status register of the command block register.
The only difference from the Status register is that a read of this register does not imply Interrupt Acknowledge and INTRQ signal is not reset.
Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit | 2 | Bit | 1 | Bit 0 |
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BSY | DRDY | DF | DSC | DRQ | 0 |
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| ERR |
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