DS80C310

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POWER ON RESET

The DS80C310 will hold itself in reset during a power-up until 65,536 clock cycles have elapsed. The

power-on reset used by the DS80C310 differs somewhat from other members of the High-Speed

Microcontroller family. The crystal oscillator may start anywhere between 1.0V and 4.5V but is not

specified. This eliminates the need for an RC reset circuit. For voltage-specific precision brownout

detection, an external component will be needed. When the device goes through a power-on reset, the

POR flag will be set in the WDCON (D8h) register at bit 6.

INTERRUPTS

The DS80C310 provides 10 interrupt sources with two priority levels. Software can assign high or low

priority to all sources. All interrupts that are new to the 8051 have a lower natural priority than the

originals.

INTERRUPT SOURCES AND PRIORITIES Table 4

NAME

DESCRIPTION

VECTOR

NATURAL

PRIORITY

INT0

External Interrupt 0

03h

1

TF0

Timer 0

0Bh

2

INT1

External Interrupt 1

13h

3

TF1

Timer 1

1Bh

4

SCON

T1 or R1 from the serial port

23h

5

TF2

Timer 2

2Bh

6

INT2

External Interrupt 2

43h

7

INT3

External Interrupt 3

4Bh

8

INT4

External Interrupt 4

53h

9

INT5

External Interrupt 5

5Bh

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