SH7052 datasheet(577/919 Pages) RENESAS

Il numero della parte	SH7052

Spiegazioni elettronici	SuperHTM RISC engine

PDF	919 Pages

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Produttore elettronici	RENESAS [Renesas Technology Corp]

Homepage	http://www.renesas.com

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4. Unread message reception

When the identifier in a mailbox matches a receive message, the message is stored in the

mailbox. If a message overwrite occurs before the CPU reads the message, the corresponding

bit (UMSR0 to UMSR15) is set in the unread message register (UMSR). In overwriting of an

unread message, when a new message is received before the corresponding bit in the receive

complete register (RXPR) has been cleared, the unread message register (UMSR) is set. If the

unread interrupt flag (IRR9) in the interrupt mask register (IMR) is set to the interrupt enable

value at this time, an interrupt can be sent to the CPU. Figure 15.10 shows a flowchart of

unread message overwriting.

UMSR = 1

IRR9 = 1

Unread message overwrite

IMR9 = 1?

End

Yes

Interrupt to CPU

Clear IRR9

Message control/message data read

: Settings by user

: Processing by hardware

Figure 15.10 Unread Message Overwrite Flowchart

SH7052 Scheda tecnica(PDF) 577 Page - Renesas Technology Corp