Panasonic KX-TDA200BX Service Manual page 29

Functions as the bus master of EC bus (synchronous bus with 16 bit width, transmission rate max.10Mbps). Communicates
with ASIC mounted to each option card via EC bus and controls the option card.
Controls CT bus (HW clock 8.192MHz, 8 highway, 128 timeslot) for TSW function.
(A detailed description of TSW will be added later.)
Controls the conference call for 3 people x ~8 parties ~ 8 people x ~3 parties.
Generates single and DTMF tone in any highway and timeslot.
Provides the digital gain control function by data conversion.
Provides some I/O ports for CODEC channel pulse generation, modem encoding rule setting and music on hold switching
and is controlled by CPU.
· Memory block
Configuration: IC301, IC302 (SRAM), IC303 (FlashROM), IC305, IC306 (SDRAM), IC309, IC310, IC311 (logic IC) and so
on.
Function: (IC301, IC302)
Saves the user configuration data (such as key assign data per PT).
This memory is battery backup.
(IC303)
Saves (some of) the system boot program and the system data.
(IC305, IC306)
The main program is loaded from the SD card on the system start-up.
Used as the program area and the CPU work area after start-up.
Makes a direct bus connection to CPU due to high-speed action (bus clock 66MHz).
(IC309, IC310, IC311)
Generates each memory select signal from the memory area select signal and upper address. Generates the write signal
and upper/lower byte select signal.
· USB block
Configuration: IC204 (USB I/F), X201 (source clock: 12.000MHz), CN209 (USB connector) etc.
Function: Connects to the USB host system (mainly PC) via CN209 (B type connector) as a USB device and makes data
transfer by max.11Mbps. DMA function of CPU is utilized to transfer the data.
· SD card block
Configuration: IC205 (SD card I/F), IC209, X202(20MHz), CN211 (SD card connector) and so on.
Function: Loads the main program and the system data from the SD card connected to CN211 by 10Mbps. Restores the
system data periodically.
· MOH/PAGING block
Configuration: IC405, IC406 (CODEC), IC408, IC409 (OP Amp), IC410 (Melody IC), Q407~Q410 (transistor), JK401~JK404
(pin jack) etc.
Function: The external music on hold 1 is input from JK404 and is A/D converted in IC405 via AGC (Auto Gain Control)
circuit, which consists of IC408, Q407, Q409 and other CR, and then is connected to the call line HW. Likewise the external
music on hold 2 is input from JK403 and is made A/D conversion in IC406 via AGC (Auto Gain Control) circuit, which
consists of IC409, Q408, Q410 and other CR, and then is connected to the call line HW. The external music on hold 2 and
IC410 is exclusively connected to IC406 input (by software control).
The various tones & DTMF tone and the voice data generated in IC102 (ASIC) are made D/A conversion in IC405 and
IC406. They are output via JK402, JK401 respectively.
· Power Supply block
Configuration: IC402 (DC/DC converter), IC403 (1.8V regulator), IC404 (1.9V regulator), IC411 (OP Amp), IC413 (negative
power regulator), Q403, Q404, Q405, Q411, Q412 (transistor), L401, C408, C453, C454, D406~D409, BAT401, IP401,
IP402 (circuit protection device) and so on.
Function:
+15V input is made step-down to +3.3V by DC/DC converter circuit that consists of IC402, L401, Q412 and C408, and is
supplied to each IC power. Also, it monitors +3.3V output voltage and turns ON Q411 to block +15V input when over voltage
is supplied.
+15V input is dropped to +9.4V by Q403 and is supplied to RS232C driver with the inverted voltage (about 9.1V) generated
in IC413, C453 and C454.
+3.3V generated in DC/DC converter is converted to 1.8V in the back board or IC403 and Q405 via Q404 and supplied to
IC101 core power, and also is converted to 1.9V in IC404 via the back-flow prevention diode D407 and supplied to IC101
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KX-TDA200BX