STM32 Learning 014_STC89C51RC

STC89C52rc is a low-power, high-performance CMOS 8-bit controller produced by STC, with 8k bytes of system programmable FLASH memory. The stc89c51 uses the classic MCS-51 core, but has made many improvements, so that the chip has functions that the traditional 51 does not have, but has a flexible 8-bit CPU and system programmable FLASH on a single chip.

Standard functions: 8k bytes Flash, 512 bytes Ram, 32-bit I/O port lines, watchdog timer, built-in 4KBEEPROM, max810 reset circuit, 3 16-bit timers/counters, 4 external interrupts, a vector 4-level interrupt structure (compatible with the traditional 51's 5-vector 2-level interrupt structure), full-duplex serial port. In addition, stc89c52 can be reduced to 0hz static logic operation, supports two software-selectable power saving modes, in idle state, the CPU stops working, allowing RAM, timer/counter, serial port, and interrupts to continue working. In power-off protection mode, RAM contents are saved, the oscillator is frozen, and all microcontroller operations stop until the next interrupt or hardware reset. The maximum operating frequency is 35MHz, 6T/12T is optional (6T mode means--6 clock cycles are one machine cycle).

STC89C52RC is an enhanced MCS-51 microcontroller from Hongjing Company. Compared with Atmel's AT89C52, it has the following advantages:

1. Supports STC 2-wire download mode, making program download more convenient

2. Support 6T mode (in 6T mode, 6 clock cycles are one machine cycle)

3. 4kB EEPROM integrated on chip

4. With P4 port, more I/O

5. The program memory has a longer erase and write life (STC nominally can be erased 100,000 times, Atmel nominally can be erased 1,000 times. However, for mass-produced finished products, this erase and write life is meaningless)

　　Compared with Atmel, the disadvantages of STC microcontrollers are:

　　In some cases, the anti-interference ability is not as good as Atmel's MCS-51 microcontroller

Working voltage: 5.5-3.3V (5V MCU) / 3.8v-2.0v (3V MCU)

Working frequency: 0-40MHz, equivalent to 0-80MHz of ordinary 51, the actual working frequency can reach 48MHz;

The user application space is 8K bytes;

On-chip integrated 512-byte RAM;

General I/O port, reset to P1/P2/P3 is quasi-bidirectional/weak pull-up, P0 is drain output, no pull-up is required when used as a bus expansion port; when using the I/O port, a pull-up resistor is required.

ISP/IAP (In Application Programmable), no dedicated programmer or emulator is required, user programs can be directly downloaded through the serial port (RXD/P3.0, TXD/P3.1), and one piece can be completed in seconds;

With EEPROM function;

There are three 16-bit timers/counters, T0, T1, T2;

4 external interrupts, falling edge or low level trigger circuit, POWER down mode can be awakened by external interrupt low level trigger interrupt

Universal asynchronous serial (UART), you can also use timer software to implement multiple UARTs;

PDIP package;