Panasonic KX-TDA600BX, Service Manual

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8.1.4. Circuit Description
8.1.4.1. Outline of Block Description
• • • • CPU block
This block operates the main unit control. Besides this operates various controls, select signal generation, DMA control and
serial port control. This contains the built-in clock function.
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ASIC block
This provides the communication function between each option card, call control (TSW function), conference call, tone
generation and gain control function.
• • • • Memory block
This is a work area and the main unit control program storage or the system boot program storage or the user configuration data
storage area.
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USB block
This provides the USB I/F function. Connects to the PC to be used for the PC programming or the system data load/store.
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SD card block
This provides the SD card I/F function and loads the main unit program and the system data from the SD card storing the main
unit control program.
• • • • MOH/PAGING block
This provides the external music on-hold input x 2, the external paging output x 2 port. And also this provides the external music
on-hold input 1 system and exclusively the internal music on-hold output.
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Power block
This consists of DC/DC converter circuit and various regulators.
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RTC block
This provides the Real time clock function when system stops.
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BUS-M interface block
This provides the control interface between EMPR Card and BUS-M Card.
8.1.4.2. Detail of Block Description
• • • • CPU block
Configuration: IC200 (CPU), IC207 (reset IC), IC206 (spread spectrum clock IC), X201 (clocking clock) and so on.
Function:
(IC200) Generates the select signal in accordance with the memory map and operates Readout/Storage of data between each
peripheral.
Controls the DMA transfer between USB I/F or built-in serial controller and memory.
Operates input/output control of each I/O signal in accordance with the program.
Contains the built-in clock function with the source clock X201 (32.768 kHz).
(IC207) Monitoring the power voltage, it generates the reset signal when the voltage drops to under the constant value
(2.9Vtyp).
(IC206) To reduce the unnecessary radiation, it generates the clock with the constant blurring mainly X104 clock output (16.384
MHz).
Signal Name Function
+15VIN +15V DC
+15V +15V DC for MOH circuit
3.3V_BB +3.3V DC
For pull-up of back board signal line (not in use)
+3.3VB +3.3V DC
Backup by a battery For SRAM (IC621, IC622) RTC
1.5V +1.5V DC for CPU (IC200) core
A[0]-A[25] Address bus
nAC_ALM AC alarm signal: This indicates AC voltage cutoff. (L: Alarm condition)
nBACK Bus Acknowledge
nBATT This indicates whether external battery is connected or not.L: Connected
nBAT_ALM Battery Alarm Signal: This indicates the declined voltage of lithium battery. (L: Alarm condition)
nBREQ Bus Request
nBS Bus Cycle Start
nRD/nCAS Column Address Strobe: CAS signal for SDRAM
nRAS Row Address Strobe: RAS signal for SDRAM
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KX-TDA600BX