LG MG810c Service Manual page 26

3. H/W Circuit Description
G. Audio Circuits
All audio functions are performed in CL8237S4(MAP) and YMU783(MIDI IC). MP3/AAC decoding is
performed in CL8237S4 and MIDI ring-tone generation and DAC function of MP3/AAC, MIDI is
performed in YMU783. All analog audio signals (including voice signal) are mixed in YMU783 using
analog mixer stage and amplified with amplifier stage for headphone and speaker.
Figure 10. Audio Block Diagram
1) MP3, AAC Decoding (Corelogic, CL8237S4)
CL8237S4 is a multimedia processor. It includes Camera Interface, NAND Interface, LCD Interface,
ARM9 Processor, etc. In MG810c, CL8237S4 uses 27MHz X-tal(X201) for system clock. For Audio
function of MG810c, CL8237S4 performs storing, decoding MP3/AAC data. MP3/AAC data is stored in
NAND-Memory, which is connected to CL8237S4 via NAND Interface(NAND_D(0~7)). The MP3/AAC
data are decoded in CL8237S4 and the decoded data is transferred to MIDI IC(YMU783) via I2S
bus(I2S_WS, I2S_SCK, I2S_SDO). I2S bus is a standard digital audio bus.
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