XR16L2552IM-F Datasheet, PDF (34/45 Pages) Exar Corporation – 2.25V TO 5.5V DUART WITH 16-BYTE FIFO

XR16L2552
2.25V TO 5.5V DUART WITH 16-BYTE FIFO
REV. 1.1.2
EFR[6]: Auto RTS Flow Control Enable
RTS# output may be used for hardware flow control by setting EFR bit-6 to logic 1. When Auto RTS is
selected, an interrupt will be generated when the receive FIFO is filled to the programmed trigger level and
RTS de-asserts to a logic 1 at the next upper trigger level. RTS# will return to a logic 0 when FIFO data falls
below the next lower trigger level. The RTS# output must be asserted (logic 0) before the auto RTS can take
effect. RTS# pin will function as a general purpose output when hardware flow control is disabled.
• Logic 0 = Automatic RTS flow control is disabled (default).
• Logic 1 = Enable Automatic RTS flow control.
EFR[7]: Auto CTS Flow Control Enable
Automatic CTS Flow Control.
• Logic 0 = Automatic CTS flow control is disabled (default).
• Logic 1 = Enable Automatic CTS flow control. Data transmission stops when CTS# input de-asserts to logic
1. Data transmission resumes when CTS# returns to a logic 0.
4.17 Software Flow Control Registers (XOFF1, XOFF2, XON1, XON2) - Read/Write
These registers are used as the programmable software flow control characters XOFF1, XOFF2, XON1, and
XON2. For more details, see Table 6.
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