SA-1100 Developer’s Manual 11-145
Peripheral Control Module

11.11.9 UART Register Locations

Table11-18 shows the registers associated with serial port 3 and the physical addresses used to
access them.
11.12 Serial Port 4 – MCP / SSP
Serial port 4 contains two separate full-duplex synchronous serial interfaces. The multimedia
communications port (MCP) provides an interface to the Philips UCB1100 and UCB1200 codecs.
Both devices have an audio codec, a telecom codec, a touch-screen interface, four general-purpose
analog-to-digital converter inputs, and ten programmable digital I/O lines. The MCP interface is
used by the SA-1100 both to input and output digital data to and from the codec, and to configure
and acquire status information from the codecs’ 16 registers. The synchronous serial port (SSP) is
used to interface to a variety of analog-to-digital converters, audio and telecom codecs, memory
chips, and keypad controllers as well as other miscellaneous serial devices. The SSP supports the
National Microwire and Texas Instruments* synchronous serial protocols as well as a subset of the
Motorola* serial peripheral interface (SPI) protocol.
In MCP mode, serial port 4 controls communication between the SA-1100 and either the UCB1 100
or UCB1200. The MCP produces two 64-bit subframes per frame (totalling 128 bits per frame)
using a bit clock and frame synchronization signal. Data is communicated full-duplex via a
separate transmit and receive data line. Selecting the on-chip clock, a bit clock frequency of either
9.585 Mbps or 11.981 Mbps can be programmed. Alternatively, GPIO pin 21 can be used t o input a
bit clock from an off-chip source. This feature allows users to select a frame rate that is an exact
multiple of the desired audio/telecom sample rate. The MCP communicates to the codec in the first
of the two subframes. The second subframe is used in high-end applications to communicate with a
second stereo codec; however, this feature is not supported by the MCP. Each 64-bit subframe
contains seven different fields of information. These fields include: audio conversion data, telecom
conversion data, data valid flags, control register address, control register data, and read/write
control. Both transmit and receive data contains these seven fields. The transmit frame contains
data for D-to-A conversion as well as address, data, and control signals to write to or read from the
codec’s registers, and the receive frame contains A-to-D samples and the data returned from a read
of a codec register.
Table 11-18. Serial Port 3 Control, Data, and Status Register Locations
Address Name Description
0h 8005 0000 UTCR0 UART control register 0
0h 8005 0004 UTCR1 UART control register 1
0h 8005 0008 UTCR2 UART control register 2
0h 8005 000C UTCR3 UART control register 3
0h 8005 0010 — Reserved
0h 8005 0014 UTDR UART data register
0h 8005 0018 Reserved
0h 8005 001C UTSR0 UART status register 0
0h 8005 0020 UTSR1 UART status register 1
0h 8005 0024 –
0h 8005 FFFF — Reserved