资 源 简 介
The CY7C637xxC is an 8-bit RISC one-TIme-programmable(OTP) microcontroller. The instrucTIon set has been opTImizedspecifically for USB and PS/2 operaTIons, although the microcontrollerscan be used for a variety of other embedded applications.The CY7C637xxC features up to 16 GPIO pins to supportUSB, PS/2 and other applications. The I/O pins are groupedinto two ports (Port 0 to 1) where each pin can be individuallyconfigured as inputs with internal pull-ups, open drain outputs,or traditional CMOS outputs with programmable drive strengthof up to 50 mA output drive. Additionally, each I/O pin can beused to generate a GPIO interrupt to the microcontroller. Notethe GPIO interrupts all share the same “GPIO” interrupt vector.The CY7C637xxC microcontrollers feature an internal oscillator.With the presence of USB traffic, the internal oscillatorcan be set to precisely tune to USB timing requirements (6MHz ±1.5%). Optionally, an external 6-MHz ceramic resonatorcan be used to provide a higher precision reference for USBoperation. This clock generator reduces the clock-relatednoise emissions (EMI). The clock generator provides the 6-and 12-MHz clocks that remain internal to the microcontroller.The CY7C637xxC has 8 Kbytes of EPROM and 256 bytes ofdata RAM for stack space, user variables, and USB FIFOs.These parts include low-voltage reset logic, a Watchdog timer,a vectored interrupt controller, a 12-bit free-running timer, andcapture timers. The low-voltage reset (LVR) logic detectswhen power is applied to the device, resets the logic to aknown state, and begins executing instructions at EPROMaddress 0x0000. LVR will also reset the part when VCC dropsbelow the operating voltage range. The Watchdog timer canbe used to ensure the firmware never gets stalled for morethan approximately 8 ms.
