TMPM365FYXBG
TMPM365FYXBG is 32-bit RISC Microprocessor manufactured by Toshiba.
Description
When the multi-master function is used in I2C bus mode, if these masters start the munications simultaneously, the following phenomena may occur:
1. munications may be locked up. 2. SCL pulse widths shorten; therefore these pulses may not satisfy I2C Specifications.
1.2 Condition
These phenomena occur only when the multi-master function is used in I2C bus mode. If a single master is used, these phenomena do not occur.
1.3 Workaround
There is no workaround for these phenomena. Perform recovery process by software.
1.4 How to Recover from These Phenomena
Perform recovery process by software. By using a timer, add timeout process to check whether munication is in a lock-up state.
An example of recovery process:
1. Start a timer count synchronously with start of the transmission. 2. If a serial interface interrupt (INTSBIx) does not occur in a certain period, the MCU determines the timeout. 3. If the MCU determines the timeout, munications may be locked up. Perform software reset on the serial bus interface circuit. This circuit is initialized to release munication from the lock up state. 4. Resend transmission data.
Mostly, Process 1 to 4 are enough to recovery; however if the multiple products are connected to the same bus line, add a delay time between each product's recovery process before Process 4 (resending data) is performed. This delay makes a time difference between each master; therefore bus collision can be avoided when the data is sent again.
2015/1
Important Notices
Example: Recovery process after a timeout is detected. Timeout
Perform software reset
Am I master
No device? i = Self ID×10 (- optional)
Software timer
No
(--i) == 0 ?
Bus is free?
No Other device established munication. munication starts
Back to the main routine
2015/1
2 Transitions to Low-power Consumption Mode and Generating a Nonmaskable Interrupt
This chapter describes the precautions at which non-maskable interrupt (NMI) occurs when...
