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
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...