soft i2c vs timer intrupt (isr)

[raman00084]

i am using pic 18f4620 with ccs complier. i am constantly writing a count value in ds1307 ram (i2c 400khz), then i am running a timer interrupt for erery 500ms it will call a isr in the isr function i am togging a led. my doubt is will there be any issue in ds1307 ram count writing if interrupt comes, i am using software i2c only.

 

[KlausST]

Hi,

Datasheets will tell you.

You have some options.
1) an i2c write to the ds1307 should be short in time, so maybe it's possible to disable interrupts during the i2c access. This causes a short delay to the ISR.

2) Check how much time the ISR max. needs. Then check ds1307 datasheet if this delay at any time of the i2c communication will cause problems.

Klaus