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System Expansion Options
Copyright © ARM Limited 2000. All rights reserved.
B-7
B.6
FPGA and AC97 CODEC Interface
Note
The FPGA and AC97 interface connector (JP29) are not used or fitted in the standard
product variants.
Circuitry is provided to support a Xilinx XC4036XLA FPGA. The circuitry includes
unbuffered upper address lines and DRAM control lines,
MBREQ
,
MBGNT
, a full
32-bit buffered data bus, and lower order buffered address lines.
This allows the FPGA to act as a memory mapped peripheral and to implement a
DRAM memory controller for a multi-master environment.
Provision has also been made to allow prototyping of an AC ’97 codec. The codec
interface is a serial bus that allows connection of modems, or a high-quality audio codec
of up to 20-bits resolution and with up to 6 audio channels for surround sound.
The configuration data for the FPGA is held in an 8-bit FLASH ROM (AT49LV040).
The FPGA automatically loads the data at power up, using its master parallel
configuration mode. An LED can be driven from the FPGA to show that it has finished
configuration. The configuration PROM is placed in a socket allowing its removal for
programming.
Most of the unused IO pins of the FPGA are connected to a 40-way expansion
connector, JP26, for use by alternate functions.
The AC ’97 codec interface logic essentially consists of an interface to the SA-1100
memory bus, 4 transmit FIFOs, 4 receive FIFOs, serializing, plus control and muxing
logic. The interface to the codec is a serial bus running at a bit clock rate of 12.288 MHz
and a fixed frame rate of 48 KHz. Each frame is divided into 13 time slots that carry
data for different codec channels. For full details of the interface please refer to the
AC’97 interface specification. An oscillator module is needed on the CPU board to
supply the required 12.288 MHz clock.
The AC ’97 interface connects to the MDC header connector, JP29, to allow standard
MDC daughter cards to be plugged onto the CPU board. The two smallest sizes of MDC
card will fit onto the CPU board, however, there is not enough space to fit the largest
variant. Three stereo 3.5mm jack sockets and an RJ11 telephone socket are positioned
on the CPU board and connected to a header to allow a hard wired connection to the
miniature input/output connector found on MDC cards.
Содержание Prospector P1100
Страница 1: ...ARM DUI 0122A Prospector P1100 User Guide ...
Страница 4: ...iv Copyright ARM Limited 2000 All rights reserved ARM DUI 0122A ...
Страница 86: ...Hardware Description 3 54 Copyright ARM Limited 2000 All rights reserved ARM DUI 0122A ...
Страница 140: ...Connector reference A 18 Copyright ARM Limited 2000 All rights reserved ARM DUI 0122A ...