MCIMX27 Motorola Semiconductor Products, MCIMX27 Datasheet - Page 11

• Manufacturer Part Number: MCIMX27
• Manufacturer: Motorola Semiconductor Products

This host controller supports interface protocols as specified in ATA/ATAPI-6 standard:
Before accessing the ATA bus, the host must program the timing parameters to be used on the ATA bus.
The timing parameters control the timing on the ATA bus. Most timing parameters are programmable as a
number of clock cycles (1 to 255). Some are implied. All of the ATA device-internal registers are visible
to users, and they are defined as mirror registers in ATA host controller. As specified in ATA/ATAPI-6
standard, all the features/functions are implemented by reading/writing to the device’s internal registers.
There are basically two protocols that can be active at the same time on the ATA bus, as follows:
2.3.6
The Digital Audio MUX (AUDMUX) provides programmable interconnecting for voice, audio, and
synchronous data routing between host serial interfaces—for example, SSI, SAP, and peripheral serial
interfaces—such as, audio and voice codecs. The AUDMUX allows audio system connectivity to be
modified through programming, as opposed to altering the design of the system into which the chip is
designed. The design of the AUDMUX allows multiple simultaneous audio/voice/data flows between the
ports in point-to-point or point-to-multipoint configurations.
Included in the AUDMUX are two types of interfaces. The internal ports connect to the processor serial
interfaces, and the external ports connect to off-chip audio devices and serial interfaces of other processors.
A desired connectivity is achieved by configuring the appropriate internal and external ports.
The module includes full 6-wire SSI interfaces for asynchronous receive and transmit, as well as a
configurable 4-wire (synchronous) or 6-wire (asynchronous) peripheral interface. The AUDMUX allows
each host interface to be connected to any other host or peripheral interface in a point-to-point or
point-to-multipoint (network mode).
Freescale Semiconductor
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PIO mode 0, 1, 2, 3, and 4
Multiword DMA mode 0, 1, and 2
Ultra DMA modes 0, 1, 2, 3, and 4 with bus clock of 50 MHz or higher
Ultra DMA mode 5 with bus clock of 80 MHz or higher
The first and simplest protocol (PIO mode access) can be started at any time by the ARM926 to
the ATA bus. The PIO mode is a slow protocol, mainly intended to be used to program an ATA disc
drive, but also can be used to transfer data to/from the disc drive.
The second protocol is the DMA mode access. DMA mode is started by the ATA interface after
receiving a DMA request from the drive, and only if the ATA interface has been programmed to
accept the DMA request. In DMA mode, either multiword-DMA or ultra-DMA protocol is used
on the ATA bus. All transfers between FIFO and the host IP or DMA IP bus are zero wait states
transfer, so a high-speed transfer between FIFO and DMA/host bus is possible.
Digital Audio MUX (AUDMUX)
i.MX27 Data Sheet, Advance Information, Rev. 0.1
Preliminary—Subject to Change Without Notice
Functional Description and Application Information
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