June 21, 2004 Mountain View, CA, and Austin, TX -- With passive optical network (PON) deployments sizzling in Japan and simmering in the United States, it's not surprising to find that IC vendors have upped their investments in PON chip development. The ATM-based broadband PON (BPON) space is particularly active, with BroadLight Inc. introducing a BPON controller last week and Freescale Semiconductor (recently spun out of Motorola) unveiling an SoC for CPE today.
BroadLight's new XL230 controller, aimed at optical line terminal (OLT) equipment in the central office, complements its existing XN230 BPON MAC for optical network terminal (ONT) devices at the customer end point. The company also makes optical transceivers for PONs. According to company CEO Andrew Vought and Vice President, Products Didi Ivancosky, the new device makes BroadLight the only vendor to have an end-to-end product line that includes both optical and electronic PON components, as well as software stacks.
The new device supports "extended BPON," an ITU-T-approved extension of the basic ITU G.983 PON recommendation. The extension boosts downstream bandwidth to 1.25 Gbits/sec, rather than the 622 Mbits/sec common to BPONs. The device will accommodate transmission to 63 ONUs; an enhanced UTOPIA interface enables designers to use multiple XL230s on a single board and control them with a single processor.
The XL230 also supports a BroadLight patent-pending dynamic bandwidth allocation (DBA) scheme. The device is currently sampling.
For its part, Freescale has combined the attributes of its MC92701 BPON device announced last year with its e300 core (a PowerPC processor core design), Ethernet MACs, and clock and data recovery. The new MPC8340BPON is aimed squarely at the Japanese market, according to Niket Jindal, business development and marketing manager, SemiCustom Operations, at Freescale. The onset of mass deployments there has shifted the focus of system vendors from developing equipment that works to lowering costs ¿ and the integration of several functions into a single SoC helps achieve that goal.
Cost savings, of course, will also be welcomed in the U.S. market, Jindal points out.
The MPC8340BPON device's e300 core operates at 266 MHz and includes a 32-kB instruction cache and a 32-kB data cache. The processor platform integrates a double data rate (DDR) SDRAM memory controller, three 10/100 Ethernet controllers, dual universal asynchronous receiver/transmitter (DUART), Inter-IC (I2C) bus support, serial peripheral interface (SPI), an interrupt controller, general-purpose input output (GPIO), ATM adaptation layer 5 (AAL5) support, and UTOPIA interfaces. It also supports DBA, as well as the G.983 standard 622-Mbits/sec downstream, 155-Mbits/sec upstream.
While BroadLight has focused on providing standard devices for both ends of a PON, Freescale has opted for an ONU technology -- at least as far as standard products are concerned. Jindal says the company has worked with several system vendors on semi-custom devices that incorporate the vendors' proprietary IP, including OLT chips.
"Our approach in Japan has been to work together with the OLT providers for interoperability. And since there is interoperability in Japan, there is less of a need ¿ almost no need -- for a standard product OLT," Jindal says. "Obviously, you do need OLT devices, and so we continue with the development in a number of different ways in PON chipsets. The standard product, however, is really your mass-market product. And that's the ONT device."
Freescale expects to have the MPC8340BPON ready for initial samples in the fourth quarter of this year.
-- S. Hardy