SB16C1058-TQFP128 IK Semicon Co., Ltd, SB16C1058-TQFP128 Datasheet - Page 49

• Manufacturer Part Number: SB16C1058-TQFP128
• Description: Octal-uart Controller With 256-byte Fifo
• Manufacturer: IK Semicon Co., Ltd

7.25 Transmit FIFO Trigger Level Register (TTR, Page 4)
7.26 Receive FIFO Trigger Level Register (RTR, Page 4)
7.27 Flow Control Upper Threshold Register (FUR, Page 4)
7.28 Flow Control Lower Threshold Register (FLR, Page 4)
Operates only when 256-byte FIFO mode is enabled. It sets the trigger level of 256-byte
TX FIFO for generating transmit interrupt. Interrupt is generated when the number of data
remained in TX FIFO after transmitting through TXD pin is less than the value of TTR.
Initial value is 128d, ‘1000_0000’. And ‘0000_0000’ must not be written. If written,
unexpected operation may occur.
Operates only when 256-byte FIFO mode is enabled. It sets the trigger level of 256-byte
RX FIFO for generating receive interrupt. Interrupt is generated when the number of data
remained in RX FIFO exceeds the value of RTR(this time, timeout or interrupt is valid).
Initial value is 128d, ‘1000_0000’. And ‘0000_0000’ must not be written. If written,
unexpected operation may occur.
It can be written only when 256-byte FIFO mode is enabled and one of TX software flow
control or Auto-RTS is enabled (In 64-byte mode, it cannot be written but can be read
only, and follows the value of trigger level set in FCR[5:4]). While TX software flow control
is enabled, Xoff character is transmitted when the number of data in RX FIFO exceeds
the value of FUR. If Auto-RTS is enabled, ‘1’ is outputted on NRTS pin to report that it
cannot receive data any more. If both TX software flow control and Auto-RTS is enabled,
Xoff character is transmitted and ‘1’ is outputted on NRTS pin. The value of FUR must be
larger than that of FLR.
It can be written only when 256-byte FIFO mode is enabled and one of TX software flow
control, or Auto-RTS is enabled (In 64-byte mode, it cannot be written but can be read
only, and follows the value of trigger level set in FCR[7:6]). While TX software flow control
is enabled, Xon character is transmitted when the number of data in RX FIFO is less than
the value of FUR only if Xoff character is transmitted before. If Auto-RTS is enabled, ‘0’ is
outputted on NRTS pin to report that it can receive more data. If both TX software flow
control and Auto-RTS is enabled, Xon character is transmitted only if Xoff character is
transmitted before and ‘0’ is outputted on NRTS pin. The value of FLR must be less than
that of FUR.
OCTAL UART WITH 256-BYTE FIFO
IN16C1058
JUNE 2009
REV 1.0
49