GMS30C7201 Datasheet, PDF (253/352 Pages) Hynix Semiconductor – 60MHz operation frequency Low power consumption

Slow AMBA Peripherals
PCLK/128
28 kHz
PCLK/256
14 kHz
PCLK/512
7 kHz
scanclock is generated using PCLK (3.6864MHz).
Programmable scan rate:
6.5K times/sec
test mode scan rate
101 times/sec
50 times/sec
25 times/sec
11Byte key buffer: 11 column key scan values are stored (8 x 11 key matrix).
13.4.4 Keyboard interface controller unit operation
To start key input scanning, set the SCANEN bit and POWERDOWN bit of KBCR (Keyboard
Configuration Register) and the CLKSEL bit of the KBCR. The key scan control signal is
generated. Periodically, column scan code is saved in the 11-byte key buffer. After the 11th
column key data is stored, INTKBD is generated to make the CPU read 11 scan values.
The keyboard interface block leaves reset in power down mode. To activate the block bits [7]
and [2] of the KBCR register should be programmed HIGH, then the keyboard will be
automatically scanned according to the programmed rate, and scan data will be stored in the
KBVR registers. When all the keyboard has been scanned, an interrupt is generated, and, by
interrogating the KBVR registers, software can determine which keys have been pressed. It is
software’s responsibility to debounce the key pressed information. Keyboard key press
interrupts are generated in all PMU states except deep sleep.
13.4.5 Keyboard interface controller unit register map
The base address of the keyboard interface controller unit is 0x80022000, and the offset of any
particular register from the base address is fixed.
Bit
8 bit
11 bit
8 bit
32 bit
32 bit
32 bit
1 bit
0 bit
Address
Access (R/W)
Read location/Write location
KIC Base + 0x00
R/W
KBCR/KBCR
KIC Base + 0x04
R
TICOUT
KIC Base + 0x08
R/W
TICIN/TICIN
KIC Base + 0x0c
R
KBVR0
KIC Base + 0x10
R
KBVR1
KIC Base + 0x14
R
KBVR2
KIC Base + 0x18
R
KBSR
KIC Base + 0x1c
TCLK
This is a virtual register, used to
generate TIC CLK in test mode.
Table 13-16: Keyboard interface controller unit register memory map
GMS30C7201 Data Sheet
13-25