TMPR3911 datasheet(271/462 Pages) TOSHIBA

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Chapter 13 SIB Module

13-1

13. SIB Module

13.1 Overview

The SIB Module within the TMPR3911/12 contains holding registers, shift registers, and other logic to

support interfacing to the analog-front-end device: TC35143 and/or other optional external codec devices.

The overall sound subsystem for a PIC (Personal Information Communicator) allows playing and

recording of sounds, and consists of a single-channel 12-bit codec within TC35143, TC35143 interface

circuits for direct connection to an external microphone (MIC) and speaker, and DMA support within the

TMPR3911/12.

Similarly, the overall telecom subsystem for a PIC allows support of high-performance software modems,

and consists of a single-channel 16-bit codec within TC35143, which also includes optional echo

cancellation and interface circuits for connection to an external Data Access Arrangement (DAA), as well as

an auxiliary input/output port for supporting future wireless interfaces. The DAA provides the front-end

interface circuitry needed between the analog telephone network and the telecom codec for wireline

configurations. The front-end circuit can also include ring detect, off-hook detect, and connect detect

functions.

Audio and telecom data and control/status information (such as sampling rate, gain control, muting, clip

detect, etc.) is passed between the TMPR3911/12 and TC35143 (and/or other external codec devices) via the

SIB. Within the TMPR3911/12, the SIB Module logic provides DMA support and control/status registers for

data transfers between external system memory, the CPU core, and the SIB. SIB data transfer is always

synchronous and is frame-based, with the TMPR3911/12 side always the master source of the clock and

frame frequency and phase.

For the sound subsystem, TC35143 allows the system to digitize (using the sound codec’s ADC) the MIC

input, as well as to convert (using the sound codec’s DAC) sampled sounds (either pre-stored, synthesized,

or previously recorded) stored in system memory to an analog audio output, for routing to either a speaker

and/or headphone output. For the telecom subsystem, TC35143 allows the system to digitize (using the

telecom codec’s ADC) the telecom analog baseband receive input, and the subsequent modem baseband

signal processing can be implemented using entirely a software-based approach. TC35143 then allows the

system to convert (using the telecom codec’s DAC) the processed baseband transmit output to an analog

telecom output for routing back out the wireline or wireless port.

The SIB Module provides full-duplex DMA support for sound receive and transmit, as well as

independent DMA support for telecom receive and transmit (four total independent DMA channels). The

DMA buffers can be configured in a continuous (circular) buffer mode or a one-time (empty or fill, then

stop) buffer mode. Half-buffer and end-of-buffer DMA address counter interrupts are available, allowing the

CPU to minimize overhead and efficiently empty or fill half of the DMA buffer in a ping-pong fashion. The

DMA buffer size is programmable (up to a maximum of 16 KBytes) and the receive and transmit buffers can

be configured to either reside in different memory spaces or share the same memory space (overlapping

buffers for loopback purposes or for optimum memory allocation). Also available is a direct CPU read/write

mode for bypassing the DMA, allowing the CPU to read or write the sound or telecom data on a sample by

sample basis, if so desired.

TMPR3911 Datasheet(PDF) 271 Page - Toshiba Semiconductor