Two PSoC plays with a good dash of analog

On Sept. 8 in a post on CPLDs, I promised to have more to say on the realm where microcontrollers and programmable blocks come together. Certainly, we’ve seen Atmel, Freescale, and other players try to exploit this realm in recent months. Now comes Cypress Semiconductor with two extensions to its existing Programmable System-on-a-Chip architecture (PSoC), based on 8051 and  ARM Cortex M3.

In theory, one could ask if the PSoC3, based on the 8051, offers too much performance overlap with the M8C-based PsoC1, though Cypress has disabused me of that concern. The PSoC5, however, is Cypress’s first ARM-based product in this environment, and has turned this product category into one that can take on mid-range FPGAs directly.

Cypress’s PsOC marketing director and software engineer Jim Davis points to a big performance boost between PSoC1 and 3, regardless of the 8-bit interface, with the former rated at 4 MIPS and the latter at 33 MIPS. ARM, of course, takes PSoC5 up to 100 Dhrystone MIPS. But Davis stresses that Cypress isn’t playing a clock speed game.

Key to PSoC is a three-sector programmable architecture. General block links are handled through a programmable routing and interconnect infrastructure. The digital subsystem offers up to 24 Universal Digital Blocks (with each UDB equivalent to an 8-bit datapath processor), and related timer-counters. The analog subsystem offers such programmable blocks as SAR A/D converters, delta-sigma A/D converters, and digital filters. The core MCUs are separate from all three programmable subsystems. Cypress can distinguish the two families by CPU speed, or number of analog or digital blocks, offering seven discrete versions of PSoC3, and 15 versions of PSoC5.

Cypress has released a PSoC Creator design kit that allows placement and definition of analog blocks, enabling the kind of signal-processing accuracy in digital filters one usually sees in DSPs, and the kind of precision data acquisition one usually encounters in discrete analog products. Consequently, Davis said the two new PSoC architectures may give as much competition to certain standard analog parts as they do to mid-range FPGAs. In any event, as we predicted earlier this year, the MCU/FPGA distinctions are getting fuzzier and fuzzier over time.