I/O Expander And Keyboard - Nokia RM-333 Service Manual

RM-333; RM-334; RM-335
System Module and User Interface
3 ELVDD supply from external DC/DC converter TPS65136 (+4.6V)
4 ELVSS supply from external DC/DC converter TPS65136 (-4.9V)
EL_ON signal from Falcon display is enable for the DC/DC converter TPS65136.
Figure 73 Display interface block diagram

I/O expander and keyboard

HW53 supports LM8323 I/O Expander. I/O expander is connected to Rapido via I2C bus and Genio66 is used
as an I/O Expander interrupt pin. Keyboard matrix 6x4 is connected to I/O expander. In addition, the I/O
expander has general purpose IO's. Camera accelerator RSTX and Regulator enable, TVout Accelarator reset
and Regulator enable are connected to I/O expander GPIO's.
Issue 2 COMPANY CONFIDENTIAL Page 8 –19
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