AP160

Version 0.0

16

AMIC Technology, Inc.

PROGRAM MEMORY LOCK BITS

The AP160 has three lock bits that can be left unprogrammed(U) or can be programmed (P) to obtain the additional

features listed in the following table.

Program Lock Bits

LB1

LB2

LB3

Protection Type

1

U

U

U

No program lock features

2

P

U

U

MOVC instructions executed from external program memory are disabled from fetching

code bytes from internal memory, EA is sampled and latched on reset, and further

programming of the OPT EPROM is disabled.

3

P

P

U

Same as mode 2, but verify is also disabled.

4

P

P

P

Same as mode 3, bur external execution is also disabled.

OSCILLATOR CHARACTERISTICS

XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier. The pins can be configured for use as an

on-chip oscillator, as shown in the logic symbol. To drive the device from an external clock source, XTAL1 should be driven

while XTAL2 is left unconnected. There are no requirements on the duty cycle of the external clock signal, because the

input to the internal clock circuitry is through a divide-by-two flip-flop. However, minimum and maximum high and low times

specified in the data sheet must be observed.