Parallel interface expansion I/O chip: CH351

Application block diagram

Function introduction

  • Parallel interface operation: The CH351 chip provides a universal 8-bit passive parallel interface; Can be easily hooked up to the system bus of various 8/16/32-bit MCU, DSP, MCU; And it can coexist with multiple peripheral devices.
  • Extended GPIO: ? 32 GPIO are divided into 4 groups, and a single parallel interface operation corresponds to a group of 8 GPIO pins; ? Inside the CH351 chip, each GPIO pin has a direction control bit and an internal output data bit, respectively; ? The extended GPIO pin input of the CH351 chip is compatible with CMOS and TTL levels, and has built-in weak pull-up resistors; ? Output CMOS level, compatible with TTL level, and low level 10mA high level 5mA drive capability.
  • Interrupt: The CH351 chip provides an active-low interrupt request output pin INT#; ? Can be connected to the interrupt input pin or common input pin of the microcontroller; The CH351 will generate an interrupt request when the GPIO pin whose direction control bit is set to input is low. Reset: The reset pin RST# of the CH351 chip is used to restore the CH351 to the default state; When the RST# input is low, the internal output data bits of the X0~X31 pins all return to the state of 1; And the direction control bits of X0~X31 all return to 0, that is, return to the input state.