NEC PD17062 - page 87

PD17062

9.26 SHIFT CLOCK FREQUENCY SETTING (39H)

9.27 IRQNC (3FH)

IRQNC is an interrupt request flag that indicates the interrupt request state.

When an interrupt request is generated, the flag is set to 1. When the request is accepted (interrupt is made),

the flag is reset to 0.

The interrupt request flag can be read and written by the program. Hence, if 1 is written, an interrupt by

software can be generated. If 0 is written, the interrupt hold status can be released. The IRQNC flag becomes

0 upon reset.

b3b2b1b0

SIO0CK3 SIO0CK2 SIO0CK0

39H

SIO0CK1

100 kHz

200 kHz

500 kHz

1 MHz

Fixed at 0

Internal clock frequency

Flag name Bit position Interrupt source

IRQNC b0INTNC pin

IRQBTM0 b1Clock timer

IRQVSYN b2VSYNC pin

IRQSIO0 b3Serial interface