8-bit Enhanced USB MCU - CH558


CH558 is an enhanced E8051 core MCU, compatible with MCS51 instruction set. 79% of its instructions are single-byte single-cycle instructions. CH558 has built-in 32K CodeFlash and 4K+256B RAM. CH558 has a built-in USB full-speed transceiver, supports USB Device mode, and supports USB2.0 full-speed (12Mbps) and low-speed (1.5Mbps) transfer. CH558 supports up to 64 bytes of data packet, with built-in FIFO, and supports DMA. CH558 provides abundant interface sources, including built-in class RS485 data transceiver, LED control card interface and fast level capture function. CH558 also has 1 SPI, 2 UARTs, 8-bit parallel port, etc. UART1 is compatible with 16C550. CH558 has 4 timers, provides 1-channel 16-bit PWM, and supports 8-channel 10/11-bit ADC.

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 32KB Code Flash, 5KB Data Flash and 3KB BootLoader. ISP through USB or UART.
  • Built-in 4KB XRAM and internal 256B RAM.
  • Built-in DMA controller supports USB and Timer3, ADC and LED control.
  • Built-in USB controller supports USB2.0 full-speed and low-speed device.
  • 4 timers/counters. 3-channel signal capture and 1-channel PWM output.
  • 2 full-duplex UARTs. UART1 has built-in 8-byte FIFO and supports class RS485 mode data reception/transmission.
  • One SPI communication interface, with built-in FIFO, supports master/slave mode.
  • 8-channel 10/11-bit ADC multiplexed with GPIO.
  • Built-in clock and PLL. An external crystal oscillator is also supported.
  • Packages: SSOP20, LQFP48.

Technical Resources

Downloading: USB interface / UART For CH558 reference routines, please refer to CH559 directly. The pin/program of CH558 is compatible with that of CH559, and the CH559EVT evaluation board can be used directly for development.

  1. CH558DS1.PDF(CH558 datasheet)
  2. Tool: WCHISPTool_Setup.exe
  3. CH559EVT.ZIP,contains:
    • CH559 reference routines (C programming language)
    • CH559EVT evaluation board schematic and PCB