Microchip has introduced a 32-bit microcontroller core, buying in an architecture for the first time. The firm has gone for the M4K core from MIPS Technologies.
Maximum clock rate is 72MHz, delivering 1.5DMips/MHz. Until now, all Microchip cores have been designed in-house. Why change?
“The 32-bit world is a lot more about applications and tools,” Microchip product marketing manager Paul Garden told EW. “You need a very good ecosystem to be successful. A lot of people in the 32bit space want an off-the-shelf development system - maybe an integrated development environment [IDE] they are using already.”
And he has a time-to-market argument. “If we had designed it ourselves I wouldn’t be having this discussion for a year or so.”
At the same time as the 32-bit core, complete tool chains were announced from: Ashling, Green Hills and Hi-Tech - including C and C++ compilers, IDEs and debuggers. “RTOS support is available from various vendors including CMX, Express Logic, FreeRTOS, Micrium, Segger and Pumpkin,” said Microchip, and in addition, “graphics display tools providers include EasyGUI, Segger, RamTeX and Micrium”.
As well as third party products, the firm has stepped its own free MPLAB IDE to v8.0 to include the 32-bit products, and the in-house C compiler is built around MIPS’s own product.
To kick off, seven 32-bit products are being offered. These are general-purpose devices and have exactly the same peripheral functions as, and are pin-for-pin compatible with, seven members of the PIC24F family. “The PIC32 is one step above where our 16-bit is,” said Garden. “We wanted to extend the portfolio without making too big a jump.”
Although peripheral functions are identical, core performance has increased considerably.
The 16-bit core clocks at 32MHz and at two clocks/cycle delivers 16Mips, whereas the 32-bit core operates at one clock/cycle and runs at 72MHz - 4.5x more Mips and twice the bus width.
There are four 64-pin devices and three 100-pin devices with between 32 and 512kbyte flash and 8-32kbyte RAM.
Although the peripherals are functionally the same, modifications have increased their bus interface speed to match the faster core. “The peripherals don’t degrade performance,” said Garden. “The core doesn’t have to wait around for things to happen.”
Sampling it scheduled for November with production in the second quarter of next year.
For engineers who want to play as soon as possible, Microchip has announced a $49 starter kit which includes the compiler. “You get a microcontroller on a board, a CD and a USB cable. Nothing else is needed to get up and running,” said Garden.
Why not ARM?
ARM, particularly the Cortex M4, has become popular in stand-alone microcontrollers. Why has Microchip gone with ARM’s great rival MIPS?
“They are the two vendors that bubbled to the top and we had a lot of discussions with both,” said PIC32 product marketing manager Paul Garden.
In a nutshell, according to Gardner the MIPS M4K offered a smaller core once synthesised, more DMips/MHz, and more in-core registers; as well as an extendable instruction set and a cheaper C compiler.