CCS/LP87702-Q1: Window watchdog

xlp

Part Number: LP87702-Q1

Tool/software: Code Composer Studio

When i set register WD_CTRL_1 value 0xdd,and set WD_CTRL_2 value 0x1f,the device reset in 5000ms,but it didnt restart.Probably it is in stop mode all the time .How can i restart it and go on .i read the figure number14 watchdog operation in lp87702-q1.pdf .

over 5 years ago

0 Brian Berner over 5 years ago

TI__Mastermind 30310 points

The experts of the LP87702-Q1 device are based in Europe, so it is likely they will not reply until tomorrow morning. Thank you for your patience.

0 Tuomo Alatalo over 5 years ago

TI__Intellectual 950 points

Hi,

Since WD_CTRL_2 register settings are 0x1f. It means that WD_SYS_RESTART_FLAG_MODE is 1 and that will cause stop mode. WD_SYSTEM_RESTART_FLAG need to be cleared before system restart. See clearing from WD_STATUS register, datasheet page 68

If the WD_SYS_RESTART_FLAG_MODE = 0, it is only a status bit and restart should be generated automatically.

Tuomo

0 xlp over 5 years ago in reply to Tuomo Alatalo

Intellectual 270 points

But when can i clear WD_SYSTEM_RESTART_FLAG?i read the datasheet WD_CLR_SYSTEM_RESTART_FLAG can only be read.Accroding to the figure 14 of Watchdog Operation,"I2C can write control register(from all states except Stop")0652.新建 Microsoft Word 文档.docx

0 Tuomo Alatalo over 5 years ago in reply to xlp

TI__Intellectual 950 points

Hi,

Status bit WD_SYSTEM_RESTART_FLAG is set to indicate that system restart has happened. To clearing that you need to write WD_CLR_SYSTEM_RESTART_FLAG = 1.

It is true that in the datasheet it shows to be only read bit, but it can be write to 1. Writing is only for clearing the bit, it turns automatically back to 0 after clearing so it won't stay to 1. That is the reason why datasheet stands it read only. Some datasheets it is marked as W1C, which is same "Write 1 to Clear"

If you look at the interrupts as well, the behavior of the bit is same.

Tuomo

0 xlp over 5 years ago in reply to Tuomo Alatalo

Intellectual 270 points

Hi,

But What time should I write WD_CLR_SYSTEM_RESTART_FLAG = 1?

0 Tuomo Alatalo over 5 years ago in reply to xlp

TI__Intellectual 950 points

Hi,

As soon as status bit WD_SYSTEM_RESTART_FLAG is indicate that system restart has happened. Status can be cleared by writing "1" to WD_CLR_SYSTEM_RESTART_FLAG.

Tuomo

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CCS/LP87702-Q1: Window watchdog