3822 datasheet(86/328 Pages) RENESAS

86 / 328 page

APPLICATION

2.2 Interrupts

2–20

3822 GROUP USER’S MANUAL

(2) Interrupt enable bits

The interrupt enable bits are allocated to the interrupt control register 1 (address 003E16) and the

interrupt control register 2 (address 003F16).

The interrupt enable bits control the acceptance of the corresponding interrupt request.

When an interrupt enable bit is “0,” the corresponding interrupt request is disabled. If an interrupt

request occurs when this bit is “0,” the corresponding interrupt request bit is only set to “1” and this

interrupt is not accepted.

In this case, unless the interrupt request bit is set to “0” by software, the interrupt request bit remains

in the “1” state.

When an interrupt enable bit is “1,” the corresponding interrupt is enabled. If an interrupt request

occurs when this bit is “1,” this interrupt is accepted (at interrupt disable flag = “0”).

Each interrupt enable bit can be set to “0” or “1” by software.

(3) Interrupt disable flag

The interrupt disable flag is allocated to bit 2 of the processor status register. The interrupt disable

flag controls the acceptance of interrupt request.

When this flag is “1,” the acceptance of interrupt requests is disabled. When the flag is “0,” the

acceptance of interrupt requests is enabled. This flag is set to “1” with the SEI instruction and is set

to “0” with the CLI instruction.

When a main routine branches to an interrupt processing routine, this flag is automatically set to “1,”

so that multiple interrupts are disabled. To use multiple interrupts, set this flag to “0” with the CLI

instruction within the interrupt processing routine. Figure 2.2.6 shows an example of multiple inter-

rupts.

Interrupt enable bit

Interrupt sources

Interrupt request bit

Address

Bit

Address

Bit

003E16

003F16

Table 2.2.2 List of interrupt bits for individual interrupt sources

003C16

003D16

INT0

INT1

Serial I/O reception

Serial I/O transmission

Timer X

Timer Y

Timer 2

Timer 3

CNTR0

CNTR1

Timer 1

INT2

INT3

Key input

ADT/A-D conversion

3822 Datasheet(PDF) 86 Page - Renesas Technology Corp

3822 Datasheet(HTML) 86 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL