S3F80JB

INTERRUPT STRUCTURE

 

 

INTERRUPT MASK REGISTER (IMR)

The interrupt mask register, IMR (DDH, Set 1, Bank0) is used to enable or disable interrupt processing for individual interrupt levels. After a reset, all IMR bit values are undetermined and must therefore be written to their required settings by the initialization routine.

Each IMR bit corresponds to a specific interrupt level: bit 1 to IRQ1, bit 2 to IRQ2, and so on. When the IMR bit of an interrupt level is cleared to "0", interrupt processing for that level is disabled (masked). When you set a level's IMR bit to "1", interrupt processing for the level is enabled (not masked).

The IMR register is mapped to register location DDH in set 1and Bank0. Bit values can be read and written by instructions using the register addressing mode.

Interrupt Mask Register (IMR)

DDH, Set 1, Bank 0, R/W

MSB

.7

.6

.5

.4

.3

.2

.1

.0

 

 

 

 

 

 

 

 

 

LSB

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

IRQ1 IRQ0

 

 

 

 

 

 

 

 

 

IRQ2

 

 

 

 

 

 

 

IRQ3

 

 

 

 

 

 

 

 

IRQ4

 

Interrupt Level Enable Bits (7-0):

 

 

 

 

 

 

 

 

IRQ6 IRQ5

 

 

 

 

 

IRQ7

 

 

 

 

0

= Disable (mask) interrupt

 

 

 

 

 

 

 

1

= Enable (un-mask) interrupt

 

 

 

 

 

 

 

 

 

NOTE: Before IMR register is changed to any value, all interrupts must be disable. Using DI instruction is recommended.

Figure 5-6. Interrupt Mask Register (IMR)

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Samsung S3F80JB manual Interrupt Mask Register IMR