Datasheet

Rev. 1.10 8 May 16, 2011 Rev. 1.10 9 May 16, 2011
HT16K33
RAM Mapping 16*8 LED Controller Driver with keyscan
Functional Description
Power-on Reset
When power is applied, the IC is initialised by an internal power-on reset circuit. The status of the
internal circuit after initialisation is as follows:
●
System Oscillator will be in an off state
●
COM0~COM3 outputs are set to V
DD
●
COM4~COM7 outputs will be high impedance
●
All Rows pins are changed input pins
●
LED Display is in the off state.
●
Key scan stopped
●
The combined Row/INT pins are setup as ROW outputs
●
Dimming is set to 16/16duty
Data transfers on the I
2
C-bus should be avoided for 1 ms following a power-on to allow completion
of the reset action.
Standby Mode
In the standby mode, the HT16K33 can not accept input commands nor write data to the display
RAM except using the system setup command.
If the standby mode is selected with the “S” bit of the system setup register set to “0”, the status of
the standby model is as follows:
●
System Oscillator will be in the off state
●
COM0~COM3 outputs are set to VDD
●
COM4~COM7 outputs will be high impedance
●
LED Display is in the off state.
●
Key scan stopped
●
All key data and INT ags are cleared until the standby mode is canceled.
●
If the key matrix is activated (any key) or the “S” bit of the system setup register is set to “1”, the
standby mode will be canceled and will cause the device to wake-up.
●
If the “INT/ROW” bit of the ROW/INT setup register is set to “0”, all rows pins are changed to
input pins.
●
If the “INT/ROW” bit of the ROW/INT setup register is set to “1”: all rows pins are changed to
input pins except for the INT pin (output).
●
The INT pin output will remain at a high level when the “act” bit of the ROW/INT setup register
is set to “0”.
●
The INT pin output remains at a low level when the “act” bit of the ROW/INT setup register is set
to “1”.