Embedded Processor Watch

Editor: Jim Turley

In This Issue:

• AMD Uses 80186 For Network Control
• IBM Reverse-Engineers TI C54x DSP
• ARM Spins Up Extensions for Disk Drives
• ARM Signs Epson, Qualcomm, and National
• ColdFire 5206e Increases Speed, Cache
• New IC Announcements for Embedded Designers
• About Embedded Processor Watch

AMD Uses 80186 For Network Control

AMD's first foray into intelligent network controllers starts out small. The company's new Am186CC combines the modest 80186 processor core with eight serial channels, including USB and HDLC. The chip is the first of a planned series called Comm86 for networking, telecommunications, and data communications systems.

The 186CC competes with a bewildering mix of integrated microprocessors from Motorola for similar applications. Products like xDSL modems, ISDN terminal adapters, central-office line cards, and PBX systems all need intelligent, integrated devices. The boom in such applications and the plethora of embedded-CPU vendors looking for a viable niche have driven many a microprocessor into the arms of waiting OEMs. Nortel, Cisco, Bay Networks, and Cabletron consume such devices like popcorn.

Code-named Serrano, the 186CC is better characterized as a peripheral controller with a CPU lurking in the spare silicon rather than a CPU with some integrated peripherals. A rundown of its features includes four HDLC channels, two asynchronous serial channels, a USB controller, an SSI port (like I2C), 14 chip-select pins, a memory controller (for DRAM, SRAM, ROM, and flash memories), some timers, and up to 48 multiplexed general-purpose I/O pins.

AMD's new chip nestles into some of the cracks left in Motorola's exhaustive line of communications controllers that are variously based on the 68000, CPU32 (a subset of the 68000), and PowerPC cores. Motorola's prices start lower than AMD's, but even with so many chips, there's no clear one-to-one match between a Motorola device and AMD's 186CC.

Motorola's 68LC302 is priced within pennies of the $13.50 186CC but has no DRAM controller, no Ethernet, no USB, and only two HDLC channels. To add Ethernet and a DRAM controller, a customer must pay Motorola nearly $20 for the 68EN302. Adding USB moves the price up to $26 for the PowerPC 850 but loses all HDLC capability. Only the $34 PowerPC 850DH has all these features together.

In all these permutations of features, AMD's 186CC comes out on top if the system needs multiple HDLC links and either USB or DRAM control. Outside of these bounds, Motorola probably has a cheaper part for the need. With four HDLC channels, the 186CC could be more popular in telephone line-card applications than Motorola's 850DH, which has only two HDLC links and costs more than twice as much.

That leaves AMD with potential design wins in the central-office and PBX categories, but not in office printer and low-end network hub/router areas.

We expect the 186 CPU core will be updated with AMD's less modest 386 or DX5 (133-MHz 486) processor cores. A K6-based device could stand toe-to- toe with Motorola's PowerPC-based MPC860 chips. Such high-end parts have the performance headroom to manage network traffic on their own, without the assistance and extra cost of a host processor.

Like IDT, AMD already has a presence in the data communications and telecommunications markets with other kinds of chips. Its familiarity with these vendors, and the overall growth rate in these areas, should make 186CC design wins easier to obtain. As popular as the x86 architecture is, it's not significantly better supported than the venerable 68K, so issues of support tools and compilers are moot. What's at issue is the peripheral mix, and so far AMD has narrowly missed competing head-on with the 68302 family. As the Serrano product line broadens, avoiding Motorola's products will be harder.

IBM Reverse-Engineers TI C54x DSP

IBM has paid the sincerest form of flattery to Texas Instruments by announcing the culmination of its two-year project to copy TI's popular 'C54x DSP processor core. IBM's reverse-engineered core design is already sampling in the form of two standalone DSP chips, but IBM's real strategy is to procure ASIC design wins in the booming wireless market, where TI's 'C54x family reigns supreme.

The addition of the C54x DSP core is another step in IBM's strategic shift away from standard microprocessor products and toward becoming a full-line ASIC supplier. The company's recent acquisition of the ARM7 (see Microprocessor Report 3/30/98, p. 8) and picoJava (see Microprocessor Report 3/30/98, p. 8) cores, along with the recent shift away from Somerset's standard parts (Embedded Processor Watch #1), all emphasize the move toward an ASIC business.

In a nutshell, IBM's new DSP core is a fully compatible duplicate of TI's TMS320C54x family of DSP chips. To avoid any confusion, IBM even calls its core C54xDSP. IBM claims the two families are completely binary compatible, down to cycle-by-cycle timing of individual instructions and operations. This level of accuracy should allow developers to swap existing binary code between the TI and IBM versions of the chip with no discernable differences in performance or execution.

TI has recently altered the fine print in its software-licensing agreements to specifically forbid their use with non-TI silicon, apparently in anticipation of IBM's move.

Already sampling are two versions of the chip: IBM's C541 and C547 devices, which are pin-compatible with their TI namesakes. IBM builds its devices in its 0.25-micron SA-12 process in Vermont. The tight process geometry forces a move to a lower supply voltage than TI uses for its chips. IBM covers this difference by building voltage regulation onto the die, so the DSP core can run at 2.2 V (nominal) while maintaining socket compatibility with the 3.3-V TI parts.

Although the C541 and C547 DSP chips have been sampling since late last year, the version of the core for ASIC integration is still in the last stages of design. IBM expects the core design to be complete in 3Q98 and the first C54x-based ASIC should tape out in 4Q98. That schedule should put the first samples of C54x-based parts at around the middle of 1999.

As IBM continues its march toward becoming a major ASIC house, it's inevitable that it will acquire more and more cores. It was also inevitable that it would acquire at least one DSP, and TI's 'C54x was an obvious and juicy target.

ARM Spins Up Extensions for Disk Drives

ARM is developing instruction-set extensions to its popular microprocessor architecture specifically for disk drives. Although the company would not release details, the extensions are focused on "enhanced math" and "enhanced debug" abilities. The former probably refers to improved multiply-accumulate performance and other pseudo-DSP operations common for disk-drive actuators, while the latter alludes to improved real-time visibility of the CPU core after it is embedded in an ASIC.

ARM licensees Lucent and Cirrus Logic, also part of the announcement, stated their intent to use the new extensions in upcoming disk-drive controller chips. No timeline was announced for these devices, and ARM would not disclose when the extensions themselves would be ready. Like Thumb, Piccolo, and other ARM architectural extensions, the disk-drive enhancements (which have not yet been named; we suggest "Head" as an option) will be separately licensed. The company indicated the extensions will initially be grafted onto the ARM9 core; sources indicate they will work with ARM7 and ARM10 designs as well.

Fanatically cost-conscious disk-drive makers are always eager to reduce the component count of their devices, and many hard disks now include both a microcontroller (for the host interface) and a DSP (for servo control). ARM is not the only company to try unifying these disk functions, but it is the most widely licensed architecture to give it a spin. To truly combine all the disk functions into one chip, a chip maker would also need the mixed-signal (analog plus digital) experience necessary to integrate the read-channel electronics. About half of ARM's licensees have such mixed-signal capability, Lucent and Cirrus among them.

Although ARM's new extensions will probably not "transform the hard- disk-drive industry," as the company believes, the changes will give ARM9 licensees a toehold in the very high volume market for disk drives.

ARM Signs Epson, Qualcomm, and National

In other ARM news, this month's parade of new ARM licensees includes Japanese printer maker Epson, California telephone maker Qualcomm, and Cyrix purchaser National Semiconductor. The official list of ARM adherents now stands at 30. All three companies acquired a license for the nearly ubiquitous ARM7TDMI core.

National, which was long rumored to have an ARM license, garnered a synthesizable version of the core, known as ARM7TDMI-S. It is only the third company (after LSI Logic and IBM) to acquire the synthesizable version rather than ARM's traditional process-specific hard layout. National did not reveal any plans for its core, but given that ARM development has been under way for many months, new ARM-based chips are probably not far off. Epson was also tight lipped about its ARM plans, but integrated printer controllers are an obvious choice.

For its part, Qualcomm is clear about its reason for acquiring an ARM license: the company wants to extend its line of integrated controllers for cellular telephones. Specifically planned are CDMA chips for handsets, which would compete directly with VLSI Technology's similarly ARMed CDMA devices (see Microprocessor Report 6/22/98, p. 10). Qualcomm will use the ARM7 core in devices for its own handsets and will also sell some of its chips on the open market.

With ARM9 now in the hands of its semiconductor licensees (see Microprocessor Report 12/8/97, p. 10) and ARM10 due to be announced at this year's Embedded Processor Forum (October 15/16 in San Jose), the relative value of the ARM7 has fallen precipitously, and many new licensees have signed on. It seems as if AMD and Zilog are the only remaining holdouts in the ARM band.

ColdFire 5206e Increases Speed, Cache

Motorola's new version of its ColdFire 5206 processor (see Microprocessor Report 9/11/95, p. 12) offers more performance for less money. The new 5206e ramps the speed of the company's most popular ColdFire chip to 54 MHz with the help of a much larger cache and more on-chip SRAM.

The 5206e enhances its predecessor in several ways. The instruction cache grows from 512 bytes to 4K (the chip still has no data cache); the on-chip SRAM also swells drastically from 512 bytes, to 8K in size; a two-channel DMA controller has been added; and the chip now has hardware support for multiply-accumulate and division. Despite the new hardware, the 5206e does not use the ColdFire v3 core (see Microprocessor Report 9/16/96, p. 1); it is simply a v2 core with MAC/DIV instructions added.

The 5206e is housed in the same package as the 5206, making the two pin- compatible. A shift to 0.35-micron fabrication forces a move to 3.3 V. The original 5206 runs on 5 V, so PC boards may have to be redesigned to accommodate the different power supply. The new DMA controller's request pins are multiplexed with those of one of the timers.

The 5206e runs at 40 MHz and 54 MHz, a nice step up from the 33-MHz peak speed of the original 5206. Even so, the price of the chip has actually dropped. In quantities of 10,000, Motorola's suggested price is $8.29 for the 40-MHz part and $10.28 for the 54-MHz chip. (The unusual clock speed is a multiple of NTSC television scan frequency.) This is even cheaper than the $12.77 price for the 33-MHz 5206, making the original part suddenly very unattractive for any but existing designs.

For new designs, the 5206e is a good general-purpose processor with an attractive ratio of price to performance. It's not as compelling as, say, IDT's new RC32364 (Embedded Processor Watch #3), but it's on par with IBM's slower PowerPC 401GF chips. NEC's VR4305 is faster and has floating-point, but is also a bit more expensive and has no I/O at all. Like all ColdFire chips to date, the 5206e emphasizes price over performance, and that's not a bad value proposition to offer.

New IC Announcements

Editor's Note: This occasional section gives brief summaries of new chips (processors, DSPs, memory, interface, and miscellaneous other devices) that may prove useful to embedded designers, engineers, and programmers.

TMS320C549, TMS320C5410 (Texas Instruments) These 100-MIPS DSPs come in a tiny ball-grid array package measuring 12 mm on a side; with 64K words RAM, buffered serial port, 6-channel DMA. Price: $25/10,000. Samples: 4Q98; Production: 2Q99. Call TI at 800.477.8924.

DSP56309 (Motorola) Fixed-point 24-bit DSP has 102 Kbytes of on-chip RAM, which can be divided between X and Y data memory; 3.3-V supply. Price: $47.60/10,000. Production: Now. Call Motorola at 512.794.4100.

PIC12CE673 (Microchip) Microcontroller fits in 8-pin package; with 1,024 x 14-bit OTP program memory, 128 bytes of RAM, A/D converter, and 4-MHz clock rate. Price: $2.04/1,000. Production: Now. Call Microchip at 602.786.7668.

PIC16CE62x (Microchip) Microcontrollers have 128 bytes of secure EEPROM for storing serial numbers, security codes, or calibration values; with 512-2K words RAM. Price: $1.61/1,000. Production: Now. Call Microchip at 602.786.7668.

CS8952 (Cirrus Logic) Ethernet transceiver for 10/100-Mbps networks includes signal conditioning said to extend effective cable length by 60% for 10Base-T/TX networks. Price: $8/1,000. Production: Now. Call Cirrus at 512.912.3086.

S3043/S3044 (AMCC) Two-chip set for SONET/SDH/ATM and dense-wave division multiplexing (DWDM) applications supports 2.4-GHz OC-48 standards. Price: $312/100. Production: Now. Call AMCC at 619.535.4260.

ADS7818 (Burr Brown) This sampling 12-bit analog/digital converter comes in a small 8-pin DIP; 500-kHz sample rate, 11-mW power dissipation, 2.5- V reference. Price: $5.60/1,000. Production: Now. Call Burr Brown at 800.548.6132.