W528SXX

- 6 -

c. No action will be taken when the other trigger pins are pressed, because the corresponding bits

are set to "0."

LD STOP, operand:

This instruction loads the operand message into the STOP register to set the output levels of the stop

signals. The initial value of the STOP register is "XXXXX111."

a. This register is used to program the output levels of the three STOP signals, STPA, STPB,

and STPC. Only three of the bits in the register are used, as shown below (an "X" indicates

"Don't care"):

Bit:

7

6

5

4

3

2

1

0

Stop:

X

X

X

X

X

STPC

STPB

STPA

b. When a particular STOP bit is set to "1," The corresponding stop signal will be a high output;

when a bit is set to "0," the corresponding stop signal will be a low output.

EXAMPLE:

The instruction "LD STOP, 0x43" is programmed.

EXPLANATION:

a. "43" is a hexadecimal value equal to a binary value of "0100 0011."

b. These 8 bits of data represent the following settings:

X,

X,

X,

X,

X,

STPC,

STPB,

STPA

















0

1

0

0

0

0

1

1

RESULT:

a. The STPA and STPB outputs will be high outputs.

b. The STPC signal will be a low output.

c. The sixth bit "1" is a "Don't Care" bit and so has no effect on the stop signal output

settings.

LD MODE, operand:

This instruction is used to select various operating modes. It loads an operand message into the

MODE register to select one mode from each of four pairs of modes, which correspond to bits 4

through 7 of the register (bits 0 to 3 are "Don't Care" bits). The four pairs of modes and the

corresponding bits are as follows:

Bit:

7

6

5

4

3

2

1

0

MODE:

Flash/DC

LED2/STPC

TG4/LED2_STPC

45 mS/350

µS

X

X

X

X

A "1" for one of these bits selects the first of the pair of modes indicated; a "0" selects the second of

the pair. The initial value of the mode register is "1111XXXX."