Fax Modem Bundle

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

Thirteen years of field experience
Highly optimized C/assembly code
High noise and drop-out immunity
Texas Instruments XDAIS compliant
MSP Consortium M.100 compliant
Fully supported
12-month warranty/no-charge updates

Benefits

High system densities
Low integration cost
Low support costs
High customer satisfaction

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

Table(.data):
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
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.