Hitachi CinemaStar P7K500 Specifications page 26

DD0-DD15 16-bit bi-directional data bus between the host and the drive. The lower 8 lines, DD00-07,
are used for Register and ECC access. All 16 lines, DD00-15, are used for data transfer.
These are 3-State lines with 24 mA current sink capability.
DA0-DA2 Address used to select the individual register in the drive.
CS0- Chip select signal generated from the Host address bus. When active, one of the Command
Block Registers (Data, Error {Features when written}, Sector Count, Sector Number,
Cylinder Low, Cylinder High, Drive/Head and Status {Command when written} register) can
be selected. (See Table 26: "I/O address map" on page 34)
CS1- Chip select signal generated from the Host address bus. When active one of the Control
Block Registers (Alternate Status {Device Control when written}) can be selected. (See
Table 26: "I/O address map" on page 34)
RESET- This line is used to reset the drive. It shall be kept in Low logic state during power up and in
High thereafter.
DIOW- Its rising edge holds data from the host data bus to a register or data register of the drive.
DIOR- When low, this signal enables data from a register or data register of the drive onto data bus.
The data on the bus shall be latched on the rising edge of DIOR-.
INTRQ Interrupt is enabled only when the drive is selected and the host activates the nIEN bit in the
Device Control Reg. Otherwise, this signal is in high impedance state regardless of the state
of the IRQ bit. The interrupt is set when the IRQ bit is set by the drive CPU. IRQ is reset to
zero by a host read of the status register or a write to the Command Reg. This signal is a
3-State line with 24 mA sink capability.
DASP- This is a time-multiplexed signal which indicates that a drive is active, or that device 1 is
present. This signal is driven by Open-Drain driver and internally pulled up to 5 volts through
a 10kΩ resistor.
During Power-On initialization or after RESET- is negated, DASP- shall be asserted by
Device 1 within 400 ms to indicate that device 1 is present. Device 0 shall allow up to 450
ms for device 1 to assert DASP-. If device 1 is not present, device 0 may assert DASP- to
drive a LED indicator.
DASP- shall be negated following acceptance of the first valid command by device 1. At
anytime after negation of DASP-, either drive may assert DASP- to indicate that a drive is
active.
PDIAG- PDIAG- shall be asserted by device 1 to indicate to device 0 that it has completed
diagnostics. This line is pulled-up to 5 volts in the drive through a 10kΩ resistor.
Following a Power On Reset, software reset, or RESET-, drive 1 shall negate PDIAG- within
1 ms (to indicate to device 0 that it is busy). Drive 1 shall then assert PDIAG- within 30
seconds to indicate that it is no longer busy and is able to provide status.
Following the receipt of a valid Execute Drive Diagnostics command, device 1 shall negate
PDIAG- within 1 ms to indicate to device 0 that it is busy and has not yet passed its drive
diagnostics. If device 1 is present, device 0 shall wait up to 6 seconds from the receipt of a
valid Execute Drive Diagnostics command for drive 1 to assert PDIAG-. Device 1 should
clear BSY before asserting PDIAG-, as PDIAG- is used to indicate that device 1 has passed
its diagnostics and is ready to post status.
If device 1 did not assert DASP- during reset initialization, device 0 shall post its own status
immediately after it completes diagnostics and clear the device 1 Status register to 00h.
Device 0 may be unable to accept commands until it has finished its reset procedure and is
ready (DRDY=1).
Device 1 shall release PDIAG-/CBLID- no later than after the first command following a
power on or hardware reset sequence so that the host may sample PDIAG-/CBLID- in order
to detect the presence or absence of an 80-conductor cable assembly.
HITACHI Deskstar & CinemaStar P7K500 Hard Disk Drive specification (Rev 1.1)
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