Commetrex’ 60112 Fax Modem Bundle includes Commetrex’ V.21, V.27ter, V.29, and V.17 in a C-coded reference design and versions optimized for the Texas Instruments TMS320C6200 and TMS320C5400 DSPs in a TI XDAIS Algorithm Standard-conformant and Commetrex format. The optimized versions provide up to 16 simultaneous V.17 receivers for each 100-MCPS on a TI ‘C6400 or 7 simultaneous modems on the ‘C5400.

Commetrex first deployed its modems in 1994. Hundreds of developers in Asia, North America, and Europe have since licensed the technology, and dozens of OEMs have integrated the modems into proprietary embedded environments. Everyday, millions of fax pages are sent and received with Commetrex’ fax modems.

These modems have exceptional performance in high-noise and ISI channels. They can withstand large noise bursts, dropouts, and amplitude changes.

Features

Benefits

TMS320C6000 Resource Utilization

Module Performance (mega-cycles/sec) Code Space (bytes) Constants and tables (bytes) Per-Instance Memory(bytes)
Total 5.3 (V.17R) 49,656* 14,938*
V.17 transmitter 3.7 5,984 5,036 472
V.17 receiver 5.3 28,000 7,158 2076
V.27ter/V.29 transmitter** 4.6 (V.27: 4.0) 6,904 4,228 504
V.27ter/V.29 receiver** 5.1 (V.27: 5.5) 23,264 3,996 1632
V.21 transmitter 2.1 3,488 2,080 192
V.21 Receiver 3.9 4,160 1,804 200
*Total memory utilization does not equal the sum of individual modems due to common elements
**V.27ter and V.29 are table-driven and share a single code set and static data space.

‘C5400 Resource Numbers

V.21 Rec 798 words
V.21 Xmit 451 words
V.17 Rec 3030 words
V.17 Xmit 815 words
V2X Rec 2139 words
V2X Xmit 809 words
FAXC 47 words
FMDP 1294 words
Table(.data):
V21R 31 words
V17R 518 words
V17T 724 words
V2XR 592 words
V2XT 675 words
FAXC 270 words
FMDP 58 words
.const:FMDP 36 words
.bss:FMDP 10 words
Total: 12,297 words
MIPS: 11.98 (10ms buffers)
Object memory/port: 712 (16-bit) words

Bit-Error Rate performance

In general, the results of the bit-error rates of Commetrex’ modems exceed the performance of the equivalent fax modems offered by the market leader of modem “chips”. Tests were performed for three different line-impairment conditions:

1) The ideal channel where the maximum noise for the modem to have a successful three-page transmission was measured. The lower the number the greater the noise, so the better the result.

V.17 14400bps 25dB
12000 22
9600 19
7200 17
V.29/27ter 9600 21
7200 18
4800 15
2400 9

2) C2 line – maximum noise that the modem had a successful three-page transmission. Under this line condition, the modem showed only a 1~3 dB degradation compared to the ideal channel.

V.17 14400 26
12000 24
9600 21
7200 20
V.29/V27ter 9600 22
7200 21
4800 18
2400 12

3) 3002 conditioned line. The same test was performed.

V.17 14400 27
12000 27
9600 26
7200 26
V.29/V.27ter 9600 27
7200 26
4800 22
2400 19

The maximum signal to noise ratio for a bit-error rate of 1 E-5 (lower is better):

This means that Commetrex modems can operate on a signal containing higher noise and still achieve the same bit-error rate.

Ordering Information

V.21 on ‘C54/C6x-1/-2 60105
V.27 on ‘C54/C6x-1/-2 60108
V.29 fax on C6x-1/-2 60109
V.17 fax/V.33 on C6x-1/-2 60111
Fax Modem Bundle-1/-2 60112