SH7052 datasheet(575/919 Pages) RENESAS

575 / 919 page

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Interrupt and Receive Message Settings: When mailbox initialization is finished, CPU interrupt

source settings and receive message specifications must be made. Interrupt source settings are

made in the mailbox interrupt mask register (MBIMR) and interrupt mask register (IMR). To

receive a message, the identifier must be set in advance in the message control (MCx[1] to

MCx[8]) for the receiving mailbox. When a message is received, all the bits in the receive

message identifier are compared, and if a 100% match is found, the message is stored in the

matching mailbox. Mailbox 0 (MC0[x], MD0[x]) has a local acceptance filter mask (LAFM) that

allows Don’t Care settings to be made.

1. CPU interrupt source settings

When transmitting, transmission acknowledge and transmission abort acknowledge interrupts

can be masked for individual mailboxes in the mailbox interrupt mask register (MBIMR).

When receiving, data frame and remote frame receive wait interrupts can be masked. Interrupt

2. Arbitration field setting

In the arbitration field, the identifier (STD_ID0 to STD_ID10, EXT_ID0 to EXT_ID17) of the

message to be received is set. If all the bits in the set identifier do not match, the message is not

stored in a mailbox.

Example: Mailbox 1

010_1010_1010 (standard identifier)

Only one kind of message identifier can be received by MB1

Identifier 1:

010_1010_1010

3. Local acceptance filter mask (LAFM) setting

The local acceptance filter mask is provided for mailbox 0 (MC0[x], MD0[x]) only, enabling a

Don’t Care specification to be made for all bits in the received identifier. This allows various

kinds of messages to be received.

Example: Mailbox 0

010_1010_1010 (standard identifier)

LAFM

000_0000_0011 (0: Care, 1: Don’t Care)

A total of four kinds of message identifiers can be received by MB0

Identifier 1:

010_1010_1000

Identifier 2:

010_1010_1001

Identifier 3:

010_1010_1010

Identifier 4:

010_1010_1011

SH7052 Datasheet(PDF) 575 Page - Renesas Technology Corp