IF1 Command Request Register
| MessageNumber | Message Number 0x01-0x20: Valid Message Number, the Message Object in the Message RAM is selected for data transfer. 0x00: Not a valid Message Number, interpreted as 0x20. 0x21-0x3F: Not a valid Message Number, interpreted as 0x01-0x1F. |
| Busy | Busy Flag 1 = Writing to the IF1 Command Request Register is in progress. This bit can only be read by the software. 0 = Read/write action has finished. |