Datasheet

MCP2502X/5X
DS21664D-page 24 © 2007 Microchip Technology Inc.
4.4.3 TRANSMIT MESSAGE PRIORITY
There is a priority for all transmit messages, including
TXIDn and all “Output” messages.
The transmit message priority is as follows:
1. Output messages have the highest priority.
Prioritization of the individual output message
types is determined by the three bits that
determine message type, with the lowest value
having the highest priority (e.g., Read A/D Regs
is a higher priority than Read Control Regs).
2. TXID2 (Transmit auto-converted messages) has
the second-highest priority.
3. TXID1 (Command acknowledge) has the third-
highest priority.
4. TXID0 (On Bus message) has the lowest
priority.
In the event two or more messages are pending
transmission, transmit-message-prioritization will occur
and the highest message type will be sent first.
Messages that are currently transmitting will not be
prioritized.