CONTROL REGISTERSS3C84E5/C84E9/P84E9

SYM — System Mode Register

DEH

Set 1

Bit Identifier

Reset Value

Read/Write Addressing Mode

.7–.5

.4–.2

.7

.6

.5

.4

.3

.2

.1

.0

 

 

 

 

 

 

 

 

0

0

0

x

x

x

0

0

R/W

R/W

R/W

R/W

R/W

Register addressing mode only

Not used, But you must keep always 0

Fast Interrupt Level Selection Bits

0

0

0

IRQ0

 

 

 

 

0

0

1

IRQ1

 

 

 

 

0

1

0

IRG2

 

 

 

 

0

1

1

IRQ3

 

 

 

 

1

0

0

IRQ4

 

 

 

 

1

0

1

IRQ5

 

 

 

 

1

1

0

IRQ6

 

 

 

 

1

1

1

IRQ7

 

 

 

 

.1

Fast Interrupt Enable Bit

0Disable fast interrupt processing

1Enable fast interrupt processing

.0

Global Interrupt Enable Bit (note)

0Disable global interrupt processing

1Enable global interrupt processing

NOTE: Following a reset, you enable global interrupt processing by executing an EI instruction (not by writing a "1" to SYM.0).

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Samsung S3C84E5 user manual SYM System Mode Register, Deh, Fast Interrupt Level Selection Bits, Fast Interrupt Enable Bit