HDLC External Serial Interface Configuration (TSAs)
16-12
Am186™CC/CH/CU Microcontrollers User’s Manual
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Targets the following external codecs (see Table 16-3 on page 16-14):
– AMD Am79C02/03
– AMD Am79C031
– Motorola MC14555x
– National TP305x family
– National TP307x family
– AT&T T75xx family
– TI/Intel 291x family
■
Targets the following external ISDN transceivers (ISDN requires three channels):
– AMD Am79C30A/32A S/T
– Lucent T7237 U
Note: The Am186CC microcontroller does not provide the PCM codec master clocks for
GCI applications.
16.5.4.2.2
GCI Frame Sync and Clock Conversion
To support a wide variety of external PCM codecs while in GCI mode, the microcontroller
divides down the GCI clock frequency (which is twice the GCI data rate) to match the PCM
data rate. In addition to a divided-down clock, a programmable one-clock-prior-to-data
frame sync (the programmability determines where the frame sync appears relative to a B
channel time slot) provides the needed flexibility to support the targeted PCM codecs (listed
previously). These two converted signals (converted GCI frame sync and converted GCI
clock) are an output on the Am186CC microcontroller’s external communication interface
C. All codec data movement is completely external to the microcontroller and is directly
routed between the PCM codec and the GCI bus. All external PCM codecs directly
connected to the GCI bus must meet all of the following conditions:
1. Be configured to output data on the rising edge of the converted clock and input data
on the falling edge of the converted clock (for GCI bus compatibility).
2. Be able to accept a one-clock-prior-to-data frame sync.
3. Be able to accept an active High frame sync.
4. Be capable of accepting a data clock frequency of 768 KHz.
Note: The Am186CC microcontroller only provides the PCM codec data/bit clock. The
Am186CC microcontroller does not provide the PCM codec master clock(s).
Figure 16-6 and Figure 16-7 illustrate both frame sync programmability and GCI conversion,
respectively.
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Summary of Contents for Am186 CC
Page 1: ...Am186 CC CH CU Microcontrollers User s Manual Order 21914B...
Page 4: ...iv Am186 CC CH CU Microcontrollers User s Manual...
Page 18: ...Table of Contents xviii Am186 CC CH CU Microcontrollers User s Manual...
Page 24: ...Introduction xxiv Am186 CC CH CU Microcontrollers User s Manual...
Page 40: ...Architectural Overview 1 16 Am186 CC CH CU Microcontrollers User s Manual...
Page 86: ...System Overview 3 36 Am186 CC CH CU Microcontrollers User s Manual...
Page 92: ...Emulator Support 4 6 Am186 CC CH CU Microcontrollers User s Manual...
Page 112: ...DRAM Controller 6 8 Am186 CC CH CU Microcontrollers User s Manual...
Page 134: ...Interrupts 7 22 Am186 CC CH CU Microcontrollers User s Manual...
Page 186: ...Programmable I O Signals 9 8 Am186 CC CH CU Microcontrollers User s Manual...
Page 200: ...Watchdog Timer 11 6 Am186 CC CH CU Microcontrollers User s Manual...
Page 232: ...Asynchronous Serial Ports UARTs 13 24 Am186 CC CH CU Microcontrollers User s Manual...
Page 242: ...Synchronous Serial Port SSI 14 10 Am186 CC CH CU Microcontrollers User s Manual...
Page 264: ...High Level Data Link Control HDLC 15 22 Am186 CC CH CU Microcontrollers User s Manual...
Page 332: ...Universal Serial Bus USB 18 34 Am186 CC CH CU Microcontrollers User s Manual...
Page 348: ...Register Summary A 16 Am186 CC CH CU Microcontrollers User s Manual...
Page 376: ...Index Index 18 Am186 CC CH CU Microcontrollers User s Manual...