TrueSpeech® Co-Processor
PRELIMINARY/CONFIDENTIAL
Version: 1.18
9.5.2
Sample CODEC Configurations
C1
C2
SCLK
FSYNC
Description
C442H
1FF5H
2.048 MHz
8.000 KHz
8.000 KHz
8.000 KHz
Texas Instruments µ-law TP3054 CODEC
Short Frame Sync pulse
Master Mode
CO_RATE = 21
FSYNC_RATE = 255
external crystal = 4.096 MHz
AT&T 16-bit linear CODEC T7525
Short Frame Sync pulse
Master Mode
CO_RATE = 21
FSYNC_RATE = 255
C542H
C462H
1FF5H
9FF5H
2.048 MHz
2.048 MHz
external crystal = 4.096 MHz
OKI Semiconductor µ-lawmsM7543 CODEC
Long (+ wide) Frame Sync pulse
Master Mode
CO_RATE = 21
FSYNC_RATE = 255
external crystal = 4.096 MHz
Notes:
The AT&T T7525 16-bit linear CODEC requires that the FSYNC frequency be exactly 1/256 of the
SCLK frequency. When using this CODEC, the FSYNC_RATE value must be set to 255. In order to
accommodate this requirement, when operating in Master Mode, the CT8022 must be driven from a
crystal or clock source that is an exact multiple of 2.048 MHz (so that FSYNC operates at 8KHz).
For 8-bit CODECs the SCLK frequency must be at least equal to FSYNC x 16.
For 16-bit CODECs the SCLK frequency must be at least equal to FSYNC x 32.
Other CODECs may permit a range of values for the FSYNC to SCLK ratio. However, for some
CODECs (e.g. TP3054 or TP3057) the actual usable range of ratios may depend on selection of the
default or nominal ratio, based on certain control pins. Depending on the operational mode selected,
the TP3054 and TP3057 can support nominal ratios of 1:256, 1:193 and 1:192, using nominal 2.048
MHz, 1.544 MHz and 1.536 MHz values for SCLK (for 32-channel, E1 mode or 24-channel, T1
mode). Informal tests have shown that the CODECs can support ratio ranges of at least +/- 5%
centered on these nominals.
The PLL multiplication factor used to scale the XIN frequency is 11 for the CT8022. With a 4.096
MHz crystal or clock at XIN and the PLL enabled, the CT8022 will operate at 45.056 MIPS.
54
DSP GROUP, INC., 3120 SCOTT BOULEVARD CT8022A11AQC FW Revision 0118
SANTA CLARA, CA 95054 PH: 408 986 – 4300 FAX: 408 986 – 4490
All specifications are subject to change without prior notice.
ETC [ ETC ]
