Multi-channel USB MCU: CH537


Overview

The CH537 chip is an 8-bit microcontroller with a multi-channel USB bus controller embedded. The CH537 chip uses a single clock cycle RISC reduced instruction set, supports 12MHz or even 15MHz main frequency, provides 32K bytes Flash-ROM, 768 bytes of RAM and SFR, and a separate 32-level stack. It supports 12Mbps full speed or 1.5Mbps low speed USB transmission, and provides common function modules of master-slave SPI, asynchronous serial port and PWM timer/counter. Here is CH537 internal block diagram, for reference only.

Features

  • Optimized 8-bit RISC reduced instruction set, which requires only 600 instructions for USB to serial port function compatible with CH341 chip.
  • The instruction is single clock cycle (except jump), supports 15 MHz main frequency, and is fixed to 12MHz when using USB function module.
  • Provides 32K byte Flash-ROM as a quasi-EEPROM data storage area.
  • Provides 768 bytes of RAM and several SFR-specific function registers, providing a fully independent 32-level stack.
  • Built-in USB Host host controller and default USB Device device controller with built-in 3-port USB hub root hub.
  • Support 1.5Mbps low speed and 12Mbps full speed USB communication, compatible with USB V2.0, peripheral components only need crystal and capacitor.
  • The CH537X has a built-in 4-channel independent USB device controller. Each built-in HUB supports 3 USB-enabled devices.
  • The CH537L has a built-in 2 channel independent USB device controller, and each group supports 3 USB function devices through the built-in HUB.
  • Supports control transfer, bulk transfer, interrupt transfer, sync/isochronous transfer of commonly used low speed and full speed USB devices.
  • Hardware full-duplex asynchronous serial port, supporting serial communication baud rate of 50bps ~ 3Mbps.
  • The serial port supports 5, 6, 7, or 8 data bits and supports odd parity, even parity, blank, flag, and no parity.
  • Provides SPI master and device controllers with a clock speed of 24MHz.
  • 8-bit auto-reload timer 0 for generating serial port baud rate, maximum 6MHz programmable clock or 8-bit PWM output.
  • Provides 16-bit timer 1.
  • Support interrupt source: 4-bit input level change interrupt, 1-bit input edge interrupt, timer interrupt, serial port interrupt, SPI interrupt, USB interrupt.
  • Built-in power-on power-on reset, low-voltage reset, and optional watchdog reset
  • 22 general purpose I/O pins (without USB) and optional pull-up resistors.
  • The internal and I/O pin voltages support a 3.3V supply voltage or even a 3V supply voltage and support an external input 5V supply voltage.
  • LQFP48 lead-free package, compatible with RoHS.