Data Register; Device Control Register; Figure 52. Device Control Register - Hitachi IC25N040ATCS04-0 - Travelstar 40GN 40GB UDMA/100 4200RPM 2MB 2.5" IDE Hard Drive Specifications

10.5 Data Register

This register is used to transfer data blocks between the device data buffer and the host. It is also the re-
gister through which sector information is transferred on a Format Track command and the configuration
information is transferred on an Identify Device command.
All data transfers are 16 bits wide, except for ECC byte transfers, which are 8 bits wide. Data transfers are
PIO only.
The register contains valid data only when DRQ = 1 is in the Status Register.

10.6 Device Control Register

Figure 52. Device Control Register

Bit Definitions
SRST Software Reset. The device is held at reset when RST = 1. Setting RST = 0 again
enables the device. To ensure that the device recognizes the reset, the host must set
RST = 1 and wait for at least 5
-IEN Interrupt Enable. When IEN = 0, and the device is selected, the device interrupts to the
host will be enabled. When IEN = 1, or the device is not selected, the device interrupts to
the host will be disabled.
Drive Control Register
7 6 5
- – –
Hitachi Travelstar 60GH & 40GN hard disk drive specifications
4 3 2
– 1 SRST –IEN
µ
s before setting RST = 0.
69
1 0
0