High-Level Data Link Control (HDLC)
15-14
Am186™CC/CH/CU Microcontrollers User’s Manual
Figure 15-6 shows another typical transmit with auto-enable CTS enabled. At the end of
the closing flag, CTS is driven inactive. CTS is actually driven inactive at the same time as
the last bit of the byte before the flag, but it is not recognized until the next bit; therefore, a
lost CTS does not occur.
Figure 15-4
CTS Controlled Start of Transmit
Figure 15-5
CTS Controlled End of Transmit
Figure 15-6
CTS Inactive at End of Frame
15.5.5
HDLC Receiver
The receiver takes serial data, determines the frame boundaries, and transfers the data to
a 32-byte receive FIFO, where it is transferred to memory by the SmartDMA interface or
under programmed I/O control. The SmartDMA interface automatically puts the frame status
into the buffer descriptors. Programmed I/O puts the frame status into the FIFO at the end
of the frame.
The receiver functions include:
■
Mark-idle and flag-idle detection
■
Flag/abort recognition
■
Zero-bit deletion
■
CRC checking
■
Address recognition
Figure 15-7 illustrates the block diagram for the receiver.
CTS
TCLK
TXD
CTS
TCLK
TXD
TCLK
TXD
CTS
CTS
Содержание Am186 CC
Страница 1: ...Am186 CC CH CU Microcontrollers User s Manual Order 21914B...
Страница 4: ...iv Am186 CC CH CU Microcontrollers User s Manual...
Страница 18: ...Table of Contents xviii Am186 CC CH CU Microcontrollers User s Manual...
Страница 24: ...Introduction xxiv Am186 CC CH CU Microcontrollers User s Manual...
Страница 39: ...Architectural Overview Am186 CC CH CU Microcontrollers User s Manual 1 15 Figure 1 6 32 Channel Linecard CH CC...
Страница 40: ...Architectural Overview 1 16 Am186 CC CH CU Microcontrollers User s Manual...
Страница 86: ...System Overview 3 36 Am186 CC CH CU Microcontrollers User s Manual...
Страница 92: ...Emulator Support 4 6 Am186 CC CH CU Microcontrollers User s Manual...
Страница 112: ...DRAM Controller 6 8 Am186 CC CH CU Microcontrollers User s Manual...
Страница 134: ...Interrupts 7 22 Am186 CC CH CU Microcontrollers User s Manual...
Страница 186: ...Programmable I O Signals 9 8 Am186 CC CH CU Microcontrollers User s Manual...
Страница 200: ...Watchdog Timer 11 6 Am186 CC CH CU Microcontrollers User s Manual...
Страница 232: ...Asynchronous Serial Ports UARTs 13 24 Am186 CC CH CU Microcontrollers User s Manual...
Страница 242: ...Synchronous Serial Port SSI 14 10 Am186 CC CH CU Microcontrollers User s Manual...
Страница 264: ...High Level Data Link Control HDLC 15 22 Am186 CC CH CU Microcontrollers User s Manual...
Страница 332: ...Universal Serial Bus USB 18 34 Am186 CC CH CU Microcontrollers User s Manual...
Страница 348: ...Register Summary A 16 Am186 CC CH CU Microcontrollers User s Manual...
Страница 376: ...Index Index 18 Am186 CC CH CU Microcontrollers User s Manual...