Kontron KTGM45-mITX - Manual (Page 38)

KTGM45 Users Guide
KTD-N0793-O Page 38
3.7 Parallel ATA Hard Disk interface
The PATA Host Controller supports three types of data transfers:
• Programmed I/O (PIO): Processor is in control of the data transfer.
• Multi-word DMA (ATA-5): DMA protocol that resembles the DMA on the ISA bus. Allows transfer rates of
up to 66MB/s.
• Ultra DMA: Synchronous DMA protocol that redefines signals on the PATA cable to allow both host and
target throttling of data and transfer rates up to 100MB/s. Ultra DMA 100/66/33 are supported, a 80-wire
cable is required.
One parallel ATA hard disk controller is available on the board – a primary controller. Standard 3½” hard
disks or CD-ROM drives may be attached to the primary controller by means of the 40 pin IDC connector,
PATA.
On the KTGM45/mITX Plus the parallel ATA hard disk controller is shared between the PATA connector and
the CF connector.
If the CF connector is not used then two devices (a primary and a secondary device) are supported on the
PATA interface. Otherwise if the CF connector is used then only one PATA device is supported and only by
use of 40-wire cable (not 80-wire cable). Optionally use SATA HDD device(s).
In case CF card shall be used as hot plug device then it is recommended to use USB to CF adapter. (SATA
to CF adapter doesn’t support hot plug).
The signals used for the hard disk interface are the following:
Signal Description
DAA2..0 Address lines, used to address the I/O registers in the IDE hard disk.
HDCSA1..0# Hard Disk Chip-Select. HDCS0# selects the primary hard disk.
DA15..8 High part of data bus.
DA7..0 Low part of data bus.
IORA# I/O Read.
IOWA# I/O Write.
IORDYA# This signal may be driven by the hard disk to extend the current I/O cycle.
RESETA# Reset signal to the hard disk.
HDIRQA Interrupt line from hard disk.
CBLIDA This input signal (CaBLe ID) is used to detect the type of attached cable: 80-wire cable
when low input, and 40-wire cable when 5V via 10Kohm (pull-up resistor).
DDREQA Disk DMA Request might be driven by the IDE hard disk to request bus master access to
the PCI bus. The signal is used in conjunction with the PCI bus master IDE function and is
not associated with any PC-AT bus compatible DMA channel.
DDACKA# Disk DMA Acknowledge. Active low signal grants IDE bus master access to the PCI bus.
HDACTA# Signal from hard disk indicating hard disk activity. The signal level depends on the hard
disk type, normally active low. The signals from primary and secondary controller are
routed together through diodes and passed to the connector FEATURE.
The pinout of the connectors is defined in the following sections.
Connector Definitions