IK2108A

8

May 2012, Ver. 03

KEY MATRIX & KEY INPUT DATA STORAGE RAM

Key Matrix consists of 10 x 3 array as shown below:

K1

K2

K3

SG1/

KS1

SG2/

KS2

SG3/

KS3

SG4/

KS4

SG5/

KS5

SG6/

KS6

SG7/

KS7

SG8/

KS8

SG9/

KS9

SG10/

KS10

Each data entered by each key (or any combination of keys) is stored as follows and read by a READ

Command, starting from the last significant bit. When the most significant bit of the data (b0) has been

read, the least significant bit of the next data (b7) is read.

K1

K2

K3

K1

K2

K3

SG1/KS1

SG2/KS2

x

1’st byte read

SG3/KS3

SG4/KS4

x

2’nd byte read

SG5/KS5

SG6/KS6

x

3’rd byte read

SG7/KS7

SG8/KS8

x

4’th byte read

SG9/KS9

SG10/KS10

x

5’th byte read

b0

b1

b2

b3

b4

b5

b6

b7

Key press=”1”, Key no press=”0” read.