8-bit USB Multi-Host Multi-Device Enhanced MCU - CH545


CH545 is an enhanced E8051 core MCU, compatible with MCS51 instruction set. 79% of its instructions are single-byte single-cycle instructions. CH545 features fast run speed. CH545 has built-in 64KB Flash-ROM and 8K+256B RAM. CH545 has a built-in USB host controller and transceiver, and a built-in 4-port USB root-hub. CH545 supports USB Host mode and USB Device mode, and supports USB2.0 full-speed (12Mbps) and low-speed (1.5Mbps) transfer. CH545 has built-in 4 channels of full-speed composite USB device controllers and transceivers. Each composite USB device controller is composed of a device-hub and 3 functional sub-devices. CH545 supports up to 64 bytes of data packet, with built-in FIFO, and supports DMA. CH545 provides abundant interface sources, including 2 UARTs, 6-channel PWM, 14-channel capacitive touch-key, single IIC master, 4 IIC slaves and 128 RGB LED controllers, and has 2-channel SPI and 14-channel 12-bit ADC. CH545 supports voltage comparator. CH545 also has 3 timers and 2-channel signal capture, and supports up to 58 GPIOs. CH544 is a simplified MCU of CH545, without PWM module of RGB LED. CH544 only provides 2-channel composite USB device controller and 3 IICs, and others are the same as that of CH545, please refer to CH545 datasheet and technical resources directly.

System Block Diagram


  • Enhanced E8051 core CPU, the speed is 8-15 times faster than that of standard MCS51, with special XRAM data fast copy instruction.
  • Built-in 60KB Code Flash, 1KB Data Flash and 3KB BootLoader. ISP through USB and UART.
  • Built-in 8KB XRAM and internal 256B RAM.
  • Built-in USB host controller and transceiver, built-in 4-port root-hub. Support USB 2.0 full-speed and low-speed host/device. DMA capability.
  • Built-in 4-channel full-speed composite USB device controller and transceiver. Each composite device includes a device-hub and 3 functional sub-devices. DMA capability.
  • USB flash drive file-level sub-routine library that supports FAT12/FAT16/FAT32 file system, to implement read/write USB flash drives.
  • 3 timers/counters. 2-channel signal capture and 6-channel PWM output.
  • 2 full-duplex UARTs.
  • 2 SPI communication interfaces. SPI0 supports master/slave mode. SPI1 supports master mode.
  • One IIC master and 4 IIC slaves.
  • LED driver supports 384 monochrome LEDs or 128 RGB LEDs.
  • 14-channel 12-bit ADC multiplexed with GPIO.
  • 14-channel capacitive touch-key.
  • Built-in clock and PLL. An external crystal oscillator is also supported.
  • Packages: LQFP48, LQFP64.

Product Selection Guide

Technical Resources

  • Downloading: USB interface /UART
  • CH545DS1.PDF
  • Tool: WCHISPTool_Setup.exe
  • CH545EVT.ZIP contains:
  1. CH545 reference routines (C programming language)
  2. CH545EVT evaluation board schematic and introduction