AK4184 Datasheet, PDF (25/36 Pages) Asahi Kasei Microsystems – TSC with Keypad Scanner and GPIO Expander

[AK4184]
■ Keypad Data Register (PAGE 0)
The keypad data register format is shown below. KD1, KD2, KD3, KS1, KS2 and KS3 represent the number of keys
pressed. Table 24 shows a configuration of a 30-key keypad. Data of KD1, KD2, KD3, KS1, KS2 and KS3 returned
as zero represents a no key pressed. The AK4184 keypad scanner can be read out up to three keys simultaneously.
The AK4184 key pad scanner writes the number of keys pressed in the keypad data register. For example: When two
keys are pressed at the same time, the contents of the keypad register are filled with KD1, KD2, KS1, and KS2. KD3
and KS3 are the zero data. When more than four keys are pressed at the same time, error bits (DERR bit and SERR
bit) are set to “1” and KD1, KD2, KD3, KS1, KS2, and KS3 data are set to 31.
The keypad data can be read out either from the KPDATA1 register or the KPDATA2 register. The KPDATA1
register represents the keypad data masked by the keypad column mask register. KPDATA2 register represents the
keypad data masked by both the keypad column mask register and the keypad mask register. KPDATA1 and
KPDATA2 register are cleared after these resisters are read. .
Addr NAME D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
00H KPDATA1 DERR
KD3[4:0]
KD2[4:0]
KD1[4:0]
01H KPDATA2 SERR
KS3[4:0]
KS2[4:0]
KS1[4:0]
Table 21. Keypad Data Register Format
Bits
15
14:10
9:5
4:0
Name
DERR
KD3
KD2
KD1
Description
Keypad scan data error
Keypad scan result 3. can be masked by column mask
Keypad scan result 2. can be masked by column mask
Keypad scan result 1. can be masked by column mask
Table 22. Keypad Data 1 Register (addr: 00H)
Bits
15
14:10
9:5
4:0
Name
SERR
KS3
KS2
KS1
Description
Keypad status data error
Keypad status result 3. can be masked by both keymask and column mask
Keypad status result 2. can be masked by both keymask and column mask
Keypad status result 1. can be masked by both keymask and column mask
Table 23. Keypad Data 2 Register (addr: 01H)
The corresponding number and its keypad layout are shown on Table 24.
C1 C2 C3 C4 C5 C6
R1 #1 #6 #11 #16 #21 #26
R2 #2 #7 #12 #17 #22 #27
R3 #3 #8 #13 #18 #23 #28
R4 #4 #9 #14 #19 #24 #29
R5 #5 #10 #15 #20 #25 #30
Table 24. Keypad to Key number Mapping
MS0603-E-00
25
2007/04