ATJ2073 ETC, ATJ2073 Datasheet - Page 28

• Manufacturer Part Number: ATJ2073
• Description: The Atj2073 is a Single-chip Highly-intergrated Digital Music System Solution for Devices such as Dedicated Audio Players, Pdas, and cell Phones
• Manufacturer: ETC

6.2 Key Matrix Scan
Page 28 of 45
When key scan circuit is enabled, ATJ2073 will scan the keyboard periodly. It drives pin KEYOUTn
[n=0…7] low pulse in turn . When a key is pressed, pin KEYINn connecting the key will be found low
level.
There are 12 internal 8-bit registers for key value latch per scan. But only another one register (Key Scan
Data Register ) for MCU to access key value . Those 12 internal registers are mapped into this register, and
an internal pointer is used to point to the current register to return scan data when read. Any IO write to this
register will clear the internal register, and the pointer will increase by 1 and point to the next register after
read is performed.
ATJ2073
VBAT
LOSC
VDD
VCC
POR
MCU
Actions Semiconductor Co.,LTD
JP 8003
Data Sheet