IN16C1054
7.26 Receive FIFO Trigger Level Register (RTR, Page 4)
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 128h, ‘1000_0000’ and ‘0000_0000’ must not be written. If written,
unexpected operation may occur.
7.27 Flow Control Upper Threshold Register (FUR, Page 4)
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 RTS# 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 RTS# pin. The value of FUR must be
larger than that of FLR.
7.28 Flow Control Lower Threshold Register (FLR, Page 4)
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 RTS# 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 RTS# pin. The value of FLR must be less than
that of FUR.
Table 24: SB16C1054 Reset Conditions
Registers
Reset State
Page 0
RBR
IER
[7:0] = ‘XXXX_XXXX’
[7:0] = ‘0000_0000’
[7:0] = ‘0000_0000’
[7:0] = ‘0000_0001’
FCR
ISR
Rev. 00
IKSEMICON [ IK SEMICON CO., LTD ]
