PIC architecture supports USB across 8-, 16-, and 32-bit devices
By Robert Cravotta, Technical Editor -- EDN, June 2, 2008
Microchip Technology’s USB microcontroller support now spans across 8-, 16-, and 32-bit PIC devices. New USB-device families include the 8-bit PIC18F13K50 and PIC18F14K50, the 16-bit PIC24F, and the 32-bit PIC32 USB microcontrollers. The free MPlab integrated development environment from Microchip supports software development for these microcontrollers and includes free USB-software stacks and USB class drivers that developers can use with the microcontrollers. The free USB host stack, device stack, and class drivers (HID, MSD, CDC, Custom) are available as full source code as a download from Microchip. The embedded USB-host stack consumes approximately 25 kbytes of memory on the PIC24 and PIC32 devices when using MIPS16e instructions. When using 32-bit instructions, the embedded USB-host stack consumes approximately 35 kbytes of memory.
Devices within each family are available for sampling now. The 8-bit PIC18F1XK50 microcontrollers include serial-communications interfaces, such as USB 2.0, I2CTM (inter-integrated-circuit), SPI (serial-peripheral interface) and USART universal synchronous/asynchronous receiver/transmitter. The PIC18F13K50 microcontrollers are available for $1.32 (10,000) in 20-pin SSOP, SOIC, PDIP and 5×5-mm QFN packages; the PIC18F14K50 microcontrollers are available for $1.46 (10,000). The PIC24F USB microcontroller family supports a low 2.6-μA standby current in a device that supports as much as 256 kbytes of flash and 16 kbytes of RAM. The PIC24FJ256GB1 family includes 12 devices available in 64-, 80-, or 100-pin TQFP packages with prices starting at $3.47 (10,000). The PIC32 microcontroller family includes integrated USB 2.0 OTG (On-The-Go) support and maintains pin, peripheral, and software compatibility with Microchip’s 16-bit microcontroller families. These devices support a maximum operating frequency of 80 MHz, and they include as much as 512 kbytes of flash and 32 kbytes of RAM along with the USB OTG support. The USB OTG PIC32 family member, the PIC32MX420F032H-40I/PT, is available in a 64-pin TQFP package for $3.25 (10,000).
