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6399A–DRMSD–13-Oct-08

ATSAM2553

12.4

Keyboard Configuration Register

The configuration register allows dealing with a variety of keyboards. This write only 6-bit regis-

ter is mapped at the address OBH in the I/O space.

The default configuration (power-up) is common anode (Reg[1]=0) and rubber contact

(Reg[0]=0) which corresponds to most popular keyboards.

Reg[3:2] = Scanning clock divider. (Default 00).

Reg[5:4] = Scanning matrix. (Default 00).

IO Access

IO Data

LCD_Reg[10]

DB[7:0]

RW

Comments

Write

IOD[10:0]

(IOD[9]=0)

IOD[10:0]

LCD_Reg[9]=0

IOD[7:0]

output

0

Set LCD in write mode

Write

IOD[10:0]

(IOD[9]=1)

IOD[10:0]

LCD_Reg[9]=1

LCD_D[7:0]

input

1

Set LCD in read mode

Read

xx

LCD_Reg[9]=0

LCD_Reg[7:0]

output

0

Invalid read from LCD in write mode

Read

xxx, LCD_D[7:0]

LCD_Reg[9]=1

LCD_D[7:0]

input

1

Read from LCD

Reg[0] = contact type

0 for rubber type contact

1 for spring type contact

Reg[1] = diode wiring

0 for common anode wiring

1 for common cathode wiring

Reg[3:2]}

Divide Factor

00

1

01

2

10

4

11

Not Used

Reg[5:4]}

Scanning Matrix

00

Row[2:0]

01

Row[3:0]

10

Row[4:0]

11

Not Used