tc94a48fg TOSHIBA Semiconductor CORPORATION, tc94a48fg Datasheet - Page 5

• Manufacturer Part Number: tc94a48fg
• Description: Single-chip Audio Digital Signal Processor Single-chip Audio Digital Signal Processor
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Description of Operation
ｆxi = 11.2896MHz
(44.1kHz×256)
1. Timing System
The TC94A48FG uses pulses from the XI-XO pins as the reference clock. The system is divided into blocks
that use the reference clock directly or by dividing its frequency and blocks that operate on a clock the PLL
generates based on the crystal resonation clock. The analog and microcontroller interface blocks operate on
the crystal resonation clock while the DSP block operates on the PLL-generated clock.
The system can divide the clock from the crystal and provide three types of clock from output pins.
Crystal
Input=
256fs
Xo
Xi
Figure 2 Block diagram of clock generator circuit
PLL
×1/M
Divider
PLL
REFCK
VARCK
Figure 1 Timing System
MCKO Clock
fs256
Phase
Comp.
×1/Ｎ
Dividing
5
Clock for Analog Block (256fs or 512fs)
×1/2 ～ ×1/512
Clock for Analog Block (256fs)
(LRCKO,BCKO,MCKO)
Timing output to pins
VCO
LRCKO, BCKO Clock
Clock for DSP
fs128～fs0.5
×1/Ｊ
Crystal precision
PLL-generated
TC94A48FG
2005-09-28
ADC, DAC
MAF, ΣΔ
Audio I/F
MCU I/F
DSP