in the networking market segment. This lineup of processors has wide appeal in a large variety of network equipment, from the low end to the high end of the product space.
In a recent press release, Freescale Semiconductor announced that it had shipped more than 200 million integrated communications processors.[20] Part of this success is based around the company's PowerQUICC product line. The PowerQUICC architecture has been shipping for more than a decade. It is based on a PowerPC core integrated with a QUICC engine (also called a communications processor module or CPM in the Freescale literature). The QUICC engine is an independent RISC processor designed to offload the communications processing from the main PowerPC core, thus freeing up the PowerPC core to focus on control and management applications. The QUICC engine is a complex but highly flexible communications peripheral controller.
[5] In its current incarnation, PowerQUICC encompasses four general families. For convenience, as we discuss these PowerQUICC products, we refer to it as PQ.
The PQ I family includes the original PowerPC-based PowerQUICC implementations and consists of the MPC8xx family of processors. These integrated communications processors operate at 50-133MHz and feature the embedded PowerPC 8xx core. The PQ I family has been used for ATM and Ethernet edge devices such as routers for the home and small office (SOHO) market, residential gateways, ASDL and cable modems, and similar applications.
The CPM or QUICC engine incorporates two unique and powerful communications controllers. The Serial Communication Controller (SCC) is a flexible serial interface capable of implementing many serial-based communications protocols, including Ethernet, HDLC/SDLC, AppleTalk, synchronous and asynchronous UARTs, IrDA, and other bit stream data.
The Serial Management Controller (SMC) is a module capable of similar serial-communications protocols, and includes support for ISDN, serial UART, and SPI protocols.
Using a combination of these SCCs and SMCs, it is possible to create very flexible I/O combinations. An internal time-division multiplexer even allows these interfaces to implement channelized communications such as T1 and E1 I/O.
Table 3-3 summarizes a small sampling of the PQ I product line.
Table 3-3. Freescale Select PowerQUICC I Highlights
| Feature | MPC850 | MPC860 | MPC875 | MPC885 |
|---|---|---|---|---|
| Core/speeds | PowerPC 8xx | PowerPC 8xx | PowerPC 8xx | PowerPC 8xx |
| Up to 80MHz | Up to 80MHz | Up to 133MHz | Up to 133MHz | |
| DRAM controller | Y | Y | Y | Y |
| USB | Y | N | Y | Y |
| SPI controller | Y | Y | Y | Y |
| I2C controller | Y | Y | Y | Y |
| SCC controllers | 2 | 4 | 1 | 3 |
| SMC controllers | 2 | 2 | 1 | 1 |
| Security engine | N | N | Y | Y |
