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Interrupt – Rainbow Electronics AT89C5132 User Manual

Page 97

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97

AT8xC5132

4173A–8051–08/02

Interrupt

Description

As shown in Figure 71, the MMC controller implements eight interrupt sources reported
in MCBI, EORI, EOCI, EOFI, F2FI, F1FI, and F2EI flags in MMCINT register. These
flags were detailed in the previous sections.

All of these sources are maskable separately using MCBM, EORM, EOCM, EOFM,
F2FM, F1FM, and F2EM mask bits, respectively, in MMMSK register.

The interrupt request is generated each time an unmasked flag is set, and the global
MMC controller interrupt enable bit is set (EMMC in IEN1 register).

Reading the MMINT register automatically clears the interrupt flags (acknowledgment).
This implies that register content must be saved and tested interrupt flag by interrupt
flag to be sure not to overlook any interrupts.

Figure 71. MMC Controller Interrupt System

MMC Interface

Interrupt Request

MCBI

MMINT.7

EOCM

MMMSK.5

EMMC

IEN1.0

MCBM

MMMSK.7

EORM

MMMSK.6

EOFI

MMINT.4

F2FM

MMMSK.3

EOFM

MMMSK.4

EORI

MMINT.6

F2FI

MMINT.3

EOCI

MMINT.5

F2EM

MMMSK.1

F1FM

MMMSK.2

F1EI

MMINT.0

F1EM

MMMSK.0

F1FI

MMINT.2

F2EI

MMINT.1