LG VX8610 Service Manual page 35

VX8610
2.3.4 Memory Part
MCP contents 1024Mbits NAND FLASH memory and 512Mbits SDRAM. In the NAND Flash Memory part of
MCP are programs used for terminal operation. The programs can be changed through downloading after the
assembling of terminals. On the SDRAM data generated during the terminal operation are stored temporarily.
2.3.5 Power Supply Part
When the battery voltage (+3.7V) is fed and the PWR key of keypad is pressed, U5002(PMIC) is activated by the
PWR_ON_SW signal, and The PWRON signal is held high, Buck and LDO1,2,3 are turned on; when LDO1 reaches
87% of its final value a 60ms reset timer is started at after which RESET\ is asserted high. Now the BB Processor is
initialized and will assert PWRHOLD high. PWRHOLD maintains the power on.
The two Buck converters / LDO1,2,4 in PMIC are generating the +1.4V_MSMC, +1.8V_MSMP1, +2.6V_MSMP3,
+2.8V_LCD, and +2.6V_MSMA respectively.
The Rx part LDO3 in PMIC is operated by the control signal SLEEP/ from MSM6550A
The Tx part LDO4 in PMIC is operated by the control signal IDLE/ from MSM6550A.
The TCXO part LDO5 in PMIC is operated by the control signal TCXO_EN/ from MSM6550A.
2.3.6 Logic Part
The logic part consists of internal CPU of MSM, RAM, MCP. The MSM6550A receives TCXO (=19.2MHz) from
the U1010 and controls the phone in CDMA modes. The major components are as follows:
CPU
The ARM926EJ-S microprocessor includes a 3 stage pipelined RISC architecture, both 32-bit ARM and 16-bit
THUMB instruction sets, a 32-bit address bus, and a 32-bit internal data bus. It has a high performance and low
power consumption.
MCP
NAND Flash is used to store the terminal's program. Using the down-loading program, the program can be
changed even after the terminal is fully assembled.
SDRAM is used to store the internal flag information, call processing data, and timer data.
KEYPAD
For key recognition, key matrix is setup using key encoder IC . 3 LEDs (EL lamp) and backlight circuitry are
included in the keypad for easy operation in the dark.
LCD MODULE
LCD module contains a controller which will display the information onto the LCD by 16-bit data from the
MSM6550A. It is also supplied stable +2.8V_LCD by Out6 in U5002 for wide view angle and LCD reflects to
improve the display efficiency. 4 LEDs is used to display LCD backlight.
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