Preliminary Technical Information

AD6426

This Information applies to a product under development. Its characteristics and specifications are subject to change without notice. Analog Devices assumes no

obligation regarding future manufacture unless otherwise agreed to in writing. No responsibility is assumed by Analog Devices for its use; nor for any

infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent

rights of Analog Devices.

Revision Preliminary 2.3 (June 9, ´98)

- 18 -

Confidential Information

To transform the TXPA pin into a general purpose output, set

TXPA Width = 0 (CC Control Register 75 and 76), then use

TxPA Polarity flag (CC Control Register 6) to toggle pin state.

To use the CALIBRATERADIO pin as a general purpose

output, set the AUTOCALIBRATE flag to zero and use the

CALIBRATERADIO flag to toggle pin state.

Universal System Connector Interface

A typical GSM handset requires multiple serial connections to

provide data during normal phone operation, manufacturing,

testing, and debug. In an ideal case many of these functions

could be combined into a single multi-purpose system

connector. For example, the USC port can be used for:

•

Flash code download for manufacturing and updates

•

Booting - UART interface used to download programs to

H8 memory

•

DAI Acoustic mode testing - connects System Simulator

(SS) directly to EVBC

•

DAI Transcoding mode - connects SS to 6426 for speech

codec testing

•

External DTA (Data Terminal Adapter) - asynchronous

link for MSDI interface

•

RS232 port - for on-board data services

•

H8 debug / monitor

•

Hands-free operation - time shared VBC and H8 port

•

Receive I/Q monitoring

The Universal System Connector (USC) of the 6426 is

designed such that no external glue logic is required to achieve

this multi-purpose functionality. Furthermore, since the USC’s

function is related to the voiceband and I/Q data serial ports,

the USC block is also responsible for the correct configuration

of these serial data streams.

The actual system connector has the minimum number of pins

to achieve the needed functionality. This save system pins, and

allows for a more reliable connector from a manufacturing and

mechanical standpoint. The USC defines a 5 pin connector

that multiplexes asynchronous, synchronous, and modem

control signals as needed:

Name

I/O

Function

USCRX

I

Receive Data

USCTX

O

Transmit Data

USCRTS

O

Ready to Send

USCCTS

I/O

Clear to Send / Transmit Frame Sync

USCRI

1/O

Ring Indicator / Serial Clock

Operating modes of the USC

Buffered UART Mode (Booting/Data Services)

This mode attaches the H8/DSP buffered UART to the USC,

bringing out either the serial bit rate clock or the Modem

Control Signal RI. This is the default mode when the phone is

powered up.

The BOOTCODE pin will be latched on RESET high. If

BOOTCODE is high at RESET, execution begins from the

Boot ROM which will configure the buffered UART to

download the FLASH programming code into RAM. The

FLASH program itself is also downloaded via the UART.

An external Data Terminal Adapter can also be used. In this

case Data Services are done external to the phone and then

transferred to and from the H8. With the external Data

Terminal Adapter, the serial bit rate clock output is selected

for USCRI pin.

This mode can be used for a variety of H8 debug tasks as the

UART can be used to simply shift debug information out.

Note that when in this mode if the handshake signals and

serial bit clock are not required, the RTS and RI pins can be

used as extra GPO, and the CTS pin used as an extra GPI.

Time-shared Mode (Multi-switch)

This mode allows time multiplexed communication with both

the H8 and DSP. This is most useful as a hands-free solution,

but can be used for other purposes also e.g., DAI Transcoding

Testing. This mode is used for DAI testing of the DSP’s

speech transcoder in which the DSP’s SPORT0 is connected to

the USC through the Multi-switch.

DAI Acoustic Mode Testing

This mode is used for DAI testing of the 6425’s phone’s

acoustic properties. The VSPORT of the 6425 connects to the

USC through the Multi-switch.

IQ Monitoring

This mode is used for testing the RF receive path and allows

access to the I and Q samples from the AD6425. The AD6425

signals are simply routed to the USC. This means that the

clock and frame sync are provided by the 6425 as well.

16 bit Mode

This mode connects the synchronous data path to the

SDIR/SDOR H8 Peripheral Control Registers, giving the H8

full access to the synchronous port bandwidth. This allows a

fast synchronous communication to an external device, and is

intended to be used for a fast download mechanism.