Samsung STH-N275 Service Manual

Also see for STH-N275: User guide

Contents

SAMSUNG Proprietary-Contents may change without notice6-3Circuit DescriptionTable2-1. ARM Memory MapARM Memory MapARM Address Range Data Block Size Device Name Remarks0000 0000 0000 0003 32 4 Byte Internal ROM R0000 0004 0000 1FFF 32 8K Byte Internal RAM R/W0002 0000 0002 0FFF 32 4K Byte Internal ROM R0004 0000 0005 FFFF 32/16 NA Internal Peripherals R/W0080 0000 00FF FFFF 8/16 Up to 8 M Byte SRAM_CS R/W0100 0000 017F FFFF 8/16 Up to 8 M Byte FLASH_CS R/W0180 0000 01FF FFFF 8/16 Up to 8 M Byte CS_RES1 R/W0200 0000 027F FFFF 8/16 Up to 8 M Byte CS_RES2 R/WHOST CPU (inside of BEC:U203)ARM7TDMI 32-bit microprocessor is used for the main call processing. The CPU controls all the circuitry. Thereference clock 14.4 MHz, coming from the output of the TCXO (OSC302), is connected to VCTCXO_IN (pinF3). Digital Only, additional crystal oscillator (Y201) of 32.768kHz is connected to pin B2 of the BEC. Theinterface circuitry consists of reset circuit, address bus (A0-A21), data bus (AD0-AD15), control signals(MEMWEB, MEMOEB, SRAM_CS, FLASH_CS, DISPLAY_CS, UBE etc), GPIOs, and the communication ports.The communication ports includes the UART1 and 2, the JTAG, and the SCI. The UART1 supports HPequipment interface, down loading, and data service. The UART2 and the JTAG are used for the softwaredebugging. The SCI supports the Diagnostic Monitor (DM) function.FLASH ROM (inside of U202)The 32Mbit FLASH ROM is used to store code of the application program. Using the down-loader program,this application program can be changed even after the mobile is fully assembled.SRAM (inside of U202)The 4Mbit SRAM is used to store the internal flag information, call processing data, and timer data.Key PadThe Key Pad is belong to main board. For key-press recognition, the structure of key is consisted of 8 x 3matrix, which is used GPIO input signal SCAN0-7 and GPIO output signal KEY0-2 of BEC.LCDLCD module is connected to main board directly by U103. This contains an LCD controller,. An LCD controllercontrols the information of displaying from the BEC (parallel 8-bit data) to the LCD.BASEBAND ENGIN (inside of U203)This part mainly interface with IFC (U101) and RF part. As for interface of IFC, that will be explained detail innext section. As important signals are PREAMP_G for receiver path, PA-GATE, ALC_EN for transmitter path,PLL_DATA, PLL_CLK, PLL_STRB1 for PLL synthesizer, RX_BAT, TX_BAT for power management.