12

* This specification are subject to be changed without notice.

EM73866

4-BIT MICRO-CONTROLLER FOR LCD PRODUCT

12.29.1999

ACC

CF

MSB

LSB

3

2

1

0

H REGISTER

3

2

1

0

L REGISTER

ACC

CF

MSB

LSB

EXAMPLE:

Operation

Carry Zero

8-4=4

1

0

7-F= -8(1000)

0

0

9-9=0

1

1

(3) Rotation:

There are two kinds of rotation operation, one is rotation left, the other is rotation right.

RLCA instruction rotates Acc value to left, shift the CF value into the LSB bit of Acc and the shift out data

will be hold in CF.

RRCA instruction operation rotates Acc value to right, shift the CF value into the MSB bit of Acc and the

shift out data will be hold in CF.

PROGRAM EXAMPLE: To rotate Acc right and shift a "1" into the MSB bit of Acc.

TTCFS; CF ← 1

RRCA; rotate Acc right and shift CF=1 into MSB.

HL REGISTER

HL register are two 4-bit registers, they are used as a pair of pointer for the address of RAM memory and also

2 independent temporary 4-bit data registers. For some instruction, L register can be a pointer to indicate the

pin number (Port4).

HL REGISTER STRUCTURE