SAN JOSE, Calif. Waferscale International Inc. has integrated what it calls an unprecedented amount of SRAM and flash-memory onto a new programmable storage device (PSD) for 8-bit CISC microcontroller-based systems that use high-level-language microcode.
The three-chip EasyFlash family features 8 kbytes of SRAM four times that of competing devices, according to Waferscale and a variety of flash-memory options, including a dual memory array that enables concurrent in-system programmability (ISP).
Waferscale (San Jose, Calif.) said its chip line is aimed at platforms using 8-bit MCUs like Intel Corp.'s 8051, or Motorola Inc.'s 68HCXX series. The EasyFlash features a 3,000-gate complex PLD, extra I/O, and a JTAG interface for first-time and subsequent in-system programming, as well as a special ISP decoding PLD that enables MCU-controlled in-system programming in 8-bit CISC systems.
The PSD834F3 packs 256 kbytes of flash, while the PSD833F2 and PSD834F2 sport 128 and 256 kbytes of flash-memory, respectively. The latter two devices also include a second 32-kbyte flash-memory array that enables MCU-controlled ISP by dedicating one array to execution and the other to simultaneous programming functions.
The expanded SRAM density supplements the program and data storage found in most existing MCUs, which typically have insufficient memory to handle the high-level languages like C and C++ preferred by designers for their microcode, according to Waferscale.
"Intel's 8051 MCUs typically contain 8 kbytes or less of flash memory, and Motorola's 68HC11 MCUs have no flash memory at all," said David Raun, Waferscale's vice president of marketing. "As a result, many designs done with these microcontrollers need the additional program store.
"C-language code also tends to use up more variables and stack space than assembly language," Raun continued. "It's not uncommon for these designs to require as much as 8 kbytes of SRAM substantially more than the 256 to 512 bytes on a typical 8-bit single-chip MCU. When this happens, the designer must add external SRAM, increasing board size, system cost, power consumption, and system development time."
With a two-chip solution, designers using an EasyFlash PSD and an 8-bit MCU are assured ample amounts of SRAM, code storage, and programmable logic, according to Waferscale.
"Our expectation is that the larger SRAM on the new PSDs will double our potential customer base," Raun said.
The Waferscale chips are fabricated in 0.35-micron linewidths using one of the only manufacturing processes in the industry capable of integrating flash and SRAM on the same die, the company said.
The EasyFlash family is available at prices from $7.25 to $7.90 each in quantities of 10,000.