INTERRUPTS

KS57C2308/P2308/C2316/P2316

 

 

INTERRUPT FLAGS

There are three types of interrupt flags: interrupt request and interrupt enable flags that correspond to each interrupt, the interrupt master enable flag, which enables or disables all interrupt processing.

Interrupt Master Enable Flag (IME)

The interrupt master enable flag, IME, enables or disables all interrupt processing. Therefore, even when an IRQx flag is set and its corresponding IEx flag is enabled, the interrupt service routine is not executed until the IME flag is set to logic one.

The IME flag is located in the IPR register (IPR.3). It can be directly be manipulated by EI and DI instructions, regardless of the current value of the enable memory bank flag (EMB).

IME

IPR.2

IPR.1

IPR.0

Effect of Bit Settings

 

 

 

 

 

0

 

 

 

Inhibit all interrupts

 

 

 

 

 

1

 

 

 

Enable all interrupts

 

 

 

 

 

Interrupt Enable Flags (IEx)

IEx flags, when set to logical one, enable specific interrupt requests to be serviced. When the interrupt request flag is set to logical one, an interrupt will not be serviced until its corresponding IEx flag is also enabled.

Interrupt enable flags can be read, written, or tested directly by 1-bit instructions. IEx flags can be addressed directly at their specific RAM addresses, despite the current value of the enable memory bank (EMB) flag.

Table 7-7. Interrupt Enable and Interrupt Request Flag Addresses

Address

Bit 3

Bit 2

Bit 1

Bit 0

 

 

 

 

 

FB8H

IE4

IRQ4

IEB

IRQB

 

 

 

 

 

FBAH

0

0

IEW

IRQW

 

 

 

 

 

FBCH

0

0

IET0

IRQT0

 

 

 

 

 

FBDH

0

0

IES

IRQS

 

 

 

 

 

FBEH

IE1

IRQ1

IE0

IRQ0

 

 

 

 

 

FBFH

0

0

IE2

IRQ2

 

 

 

 

 

NOTES:

1.IEx refers to all interrupt enable flags.

2.IRQx refers to all interrupt request flags.

3.IEx = 0 is interrupt disable mode.

4.IEx = 1 is interrupt enable mode.

7-12

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Samsung KS57C2308 manual Interrupt Flags, IME IPR.2 IPR.1 IPR.0