9.

CF

Carry flag.

10. SF

Status flag. jump instruction is only effective only when SF=1. SF is 1 after reset.

11. CH0, CH1, CL0, CL1

CH0, CH1, CL0 and CL1 are carrier level control registers for controlling the high and low level to (CH+1)/Fosc

and(CL+1)/Fosc. Where, Fosc is oscillator frequency, CH0 and CH1 are higher 4-bit and lower 4-bit of CH

respectively, while CL0 and CL1 are higher 4-bit and lower 4-bit of CL.

12. LL, LH

4-bit LL register, lower 4-bit of RAM addressing pointer, can be used as general register as well.

4-bit LH register, LH[0] is the MSB of RAM addressing pointer.

judging whether the circuit is working in low-voltage area to avoid incomplete code transmission. Typical

13. PR (PR, PR2)

HANGZHOU SILAN MICROELECTRONICS CO.,LTD

REV:1.1

2009.11.19

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The port mode register, which specifies the input mode or output mode of the I/O port, is 4-bit write-only. When

PR=1, the corresponding port is set to output mode. PR=0, it is set to input mode. The execution of the HOLD

instruction won’t affect the I/O modes of operation. When reset, PR=0. The port is in input mode.

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