razzor
/
twiboot
1
0
Fork 0
Code Issues 2 Pull Requests 0 Releases 6 Activity
Labels Milestones
New Issue

#1 Support I2C masters without clock-strech support

Closed
opened 1 year ago by razzor · 0 comments
razzor commented 1 year ago
Owner

Currently clock stretching is used for write/erase timing - the bus is "stopped" (by forcing SCL=low) while the AVR is writing to the flash/eeprom.

Some I2C masters (eg. BCM2835 / Raspberry Pi) do not detect SCL=low forced by the slave und continue to write data to twiboot.

Workaround could be:

  • start the actual write cycle only after STOP condition is received
  • do not acknowledge ADDR+WRITE while chip is busy writing
  • add a new read command to check if chip is buy writing

This will break existing applications since (fast) I2C transaction will now fail during chip write cycle.

Currently clock stretching is used for write/erase timing - the bus is "stopped" (by forcing SCL=low) while the AVR is writing to the flash/eeprom. Some I2C masters (eg. BCM2835 / Raspberry Pi) do not detect SCL=low forced by the slave und continue to write data to twiboot. Workaround could be: - start the actual write cycle only after STOP condition is received - do not acknowledge ADDR+WRITE while chip is busy writing - add a new read command to check if chip is buy writing This will break existing applications since (fast) I2C transaction will now fail during chip write cycle.
razzor closed this issue 11 months ago
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Apply labels
Clear labels
No items
No Label
Milestone
Set milestone
Clear milestone
No items
No Milestone
Assignees
Assign users
Clear assignees
No Assignees
1 Participants
Notifications
Due Date

No due date set.

Dependencies

This issue currently doesn't have any dependencies.

Write Preview
Loading…
Cancel
Save
There is no content yet.
Delete Branch '%!s(MISSING)'

Deleting a branch is permanent. It CANNOT be undone. Continue?

No
Yes