GMS30C7201 Datasheet, PDF (252/352 Pages) Hynix Semiconductor – 60MHz operation frequency Low power consumption

Slow AMBA Peripherals
13.4.2 Hardware interface and signal description
The Keyboard Interface Controller is connected to the APB bus.
Name
PCLK
RESET
PA
PD[31:0]
PSTB
PWRITE
PSEL
Scanout
Scanin
INTKBD
Type
In
In
In
InOut
In
In
In
Out
In
Out
Source/
Destination
UART Clock
APB Bridge
APB Bridge
APB Bridge/
Keyboard Interface
APB Bridge
APB Bridge
APB Bridge
Keypad
Keypad
Interrupt Controller
Description
UART Clock. The input frequency from UART is
3.6864MHz. PCLK is used to generate the scan clock.
Active LOW reset signal.
This is the peripheral address bus, which is used by an
individual peripheral for decoding register accesses to
that peripheral.
The addresses become valid before PSTB goes HIGH,
and remain valid after PSTB goes LOW.
This is the bi-directional peripheral data bus. The data
bus is driven by this block during read cycles (when
PWRITE is LOW).
This strobe signal is used to time all accesses on the
peripheral bus. The falling edge of PSTB is coincident
with the falling edge of BCLK.
When HIGH, this signal indicates a write to a peripheral;
when LOW, it indicates a read from a peripheral.
This signal has the same timing as the peripheral address
bus. It becomes valid before PSTB goes HIGH and
remains valid after PSTB goes LOW.
When HIGH, this signal indicates that this module has
been selected by the APB bridge. This selection is a
decode of the system address bus (ASB). For more
details, see AMBA Peripheral Bus Controller (ARM
DDI 0044).
This assigns the x-axis' scan line. The value is changed
periodically so as to cover every key matrix. During one
keyboard scan, scanout can have 11 different values.
Active LOW signal.
This indicates which key is pressed in the assigned scan
line. Active LOW signal.
Interrupt signal to the Interrupt Controller module. This
signal indicates if 11th column key scan is finished.
Active HIGH signal.
Table 13-15: Signal descriptions
13.4.3 Keyboard interface controller unit introduction
The interface controller is designed to communicate with the external keyboard. The keyboard
interface uses the pins scanin, scanout and all of the APB signal. It is possible to select one
of four scan clock modes.
Scan clock:
PCLK/2
1.84MHz, test mode
13-24
GMS30C7201 Data Sheet