UART
S3C2416X RISC MICROPROCESSOR
14-4
2.1.3 Auto Flow Control (AFC)
UART 0, UART 1 and UART 2 support auto flow control with nRTS and nCTS signals. In AFC, nCTS signals
control the operation of the transmitter, and nRTS depends on the condition of the receiver.
The UART's transmitter transfers the data in FIFO only when nCTS signals are activated(Low) (In AFC, nCTS
means that other UART's FIFO is ready to receive data or not).
Before the UART receives data, nRTS signal has to be activated(Low) when its receive FIFO has a spare space
more than 32-byte(FIFO contains less than 32-byte). And nRTS signal has to be inactivated(High) when its
receive FIFO has a spare under 32-byte(FIFO contains equal or more than
32-byte
) in case of RTS trigger level is
32byte
. (In AFC, nRTS means that its own receive FIFO is ready to receive data or not).
UART A
TxD
nCTS
UART B
RxD
nRTS
Transmission Case in UART A
UART A
RxD
nRTS
UART B
TxD
nCTS
Reception Case in UART A
Figure 14-2. UART AFC Interface
NOTE
UART 3 does not support AFC function, because the S3C2416 has no nRTS 3 and nCTS 3.
S3C2416’s AFC does not support the RS-232C interface.
Table 14-1. Example of nRTS signal change by FIFO Spare size
(In case of Reception Case in UART A)
RX side
TX side
FIFO
Contains
FIFO Spare
Space
nRTS
Signal
nRTS
Meaning
nCTS
Signal
nCTS
Meaning
33 byte
31 byte
High
Not ready to receive
High
Don’t send data to RX side
32 byte
32 byte
High
Not ready to receive
High
Don’t send data to RX side
31 byte
33 byte
Low
Ready to Receive
Low
Send data to RX side
30 byte
34 byte
Low
Ready to Receive
Low
Send data to RX side
Summary of Contents for S3C2416
Page 122: ...BUS MATRIX EBI S3C2416X RISC MICROPROCESSOR 3 4 NOTES ...
Page 204: ...DMA CONTROLLER S3C2416X RISC MICROPROCESSOR 8 18 NOTES ...
Page 284: ...WATCHDOG TIMER S3C2416X RISC MICROPROCESSOR 11 6 NOTES ...
Page 320: ...REAL TIME CLOCK S3C2416X RISC MICROPROCESSOR 13 16 NOTES ...
Page 344: ...UART S3C2416X RISC MICROPROCESSOR 14 24 NOTES ...
Page 380: ...USB2 0 DEVICE S3C2416X RISC MICROPROCESSOR 16 34 NOTES ...
Page 432: ...2D S3C2416X RISC MICROPROCESSOR 18 38 NOTES ...
Page 446: ...HS_SPI CONTROLLER S3C2416X RISC MICROPROCESSOR 19 14 NOTES ...
Page 604: ...S3C2416X RISC MICROPROCESSOR S3C2416X RISC MICROPROCESSOR 23 22 NOTES ...
Page 638: ...PCM AUDIO INTERFACE S3C2416X RISC MICROPROCESSOR 25 18 NOTES ...
Page 670: ...ELECTRICAL DATA S3C2416X RISC MICROPROCESSOR 26 32 NOTES ...