Common problem solutions for MCU

1. The watchdog current is too high

Solution: Check if there are any pins hanging in the chip without setting the status

2. What is the status of the C flag in the status register after the chip is powered on

Solution: After the chip is powered on and reset, the C flag is in an unstable state

3. How many 151 strong drivers are there

Solution: After turning on the strong drive in the 151 configuration area, the maximum current can reach about 90mA while the current remains unchanged

4. Power on at around 151 2.3V, the reset time is too long

Solution: Chip reset depends on the low-speed oscillator, and the speed of the low-speed oscillator will slow down under low voltage, so it will indeed prolong the reset time“

5. 152 B2 port cannot output normally

Answer: To check the program, initialize the OPTION register

6. How to switch to low-speed mode operation for 154

Solution: Set CLKMD to 1 and STOPHX to 1 in the SYSM register, but be sure to switch to BANK

7. Precautions for using 154 voltage comparator

Solution: After setting the LVD voltage regulator, delay for 1ms before judging LVDF, and be sure to switch to BANK

9. 154 fastest running speed

Solution: Select 8M/2T in the configuration area and enable the IHRC2X option to achieve a maximum instruction cycle speed of 8M

10. The reset point of LVD 154 is too low, and the actual test of 2V only shows 1.85V

Solution: The LVD point will be adjusted according to the process, normal

11. The written program has no problem burning to 152, but it has no functionality burning to 154

Solution: Note that the high 2 bits of FSR 154 have a BANK switching function, check for any erroneous BANK switching operations

12. The written program has no problem burning to 151, but it has no functionality burning to 154

Solution: Note that the high 2 bits of FSR 154 have a BANK switching function, check for any erroneous BANK switching operations

13. 154 forward current and reverse current

Solution: Forward push: around 15mA under VDD-0.5; Backflow: Approximately 47mAA at GND+0.5V 

14. Customer question: How to use dual clock 155

Solution: Open the IRC_RTC option in the configuration area, select the desired clock frequency, and open the T0TB bit of the OPTION register in the program

15. 155 Minimum working temperature 

solution: Normal operation can be achieved between -40 ℃ and 125 ℃

16. 155 uses 32768 for dual clock operation, resulting in significant errors

Solution: 155 external 32768 dual clock, 32768 starts oscillating slowly, about 2s

17. How to use 155/160 PWM

Solution: Ask the sales or sales assistant for PWM routines

18. The difference between 155 PWM and 701 PWM

Solution: The difference is that the PWM period of 155 can be adjusted arbitrarily, while the PWM level of 701 is fixed at 4; The duty cycle is arbitrarily adjustable

19. After powering on 155, there is a probability that the frequency will slow down

Solution: The solution is to turn off LVDR and turn on the watchdog. And it is suggested to bring back the defective products for us to test.

20. How to Simulate 701

Solution: You can first use the 153 simulator to simulate without PWM and EEPROM functions; EEPROM can be debugged on the upper computer using a programmer; PWM can ask sales or assistants for routines

21.What is the appropriate selection for the erase time configuration area of 701 EEPROM

Solution: It is recommended to choose a 120ms erase time

22. After running the 701 program to indirect addressing, the function is incorrect

Solution: Check if the program mistakenly switches BANK

23. Differences between 701/702/703

Solution: 702=XL153+256BYTE EEPROM; 701=702+3 independent PWM channels; 703=153+64BYTE EEPROM, please refer to the specification sheet for details

24.How many SECTORs are there in 701, how many addresses are there in each SECTOR, and what is the erase time

Solution: 16 SECTORs, each with 16 bytes, recommended erase time of 100ms

25. The data stored in the 701 EEPROM is incorrect

Solution: The 701 EEPROM has been tested and there are no issues. It is recommended to use the debug tool on the programmer to debug the EEPROM, or refer to the routine

26. 2711A-SOP8 cannot be burned

Solution: The adapter board needs to use a 2711A-SOP8 dedicated adapter board. You can refer to the programmer's help manual for the corresponding adapter board for the chip model burned

27. 2711 After selecting LVD_H, it cannot be burned

Solution: 2711 cannot select LVD_H, please refer to the precautions in the specification sheet for details

28. 2711 has a large voltage detection error

Solution: When using internal LDO as a reference for 2711, the accuracy is ± 2%