UART Registers
19.5.1.29 BOF Length Register (EBLR)
In IrDA SIR operation, the BOF length register (EBLR) specifies the number of BOF + xBOFs to transmit.
The value set into this register must consider the BOF character; therefore, to send only one BOF with no
XBOF, this register must be set to 1. To send one BOF with n XBOFs, this register must be set to n + 1.
Furthermore, the value 0 sends 1 BOF plus 255 XBOFs.
In IrDA MIR mode, the BOF length register (EBLR) specifies the number of additional start flags (MIR
protocol mandates a minimum of 2 start flags).
In CIR mode, the BOF length register (EBLR) specifies the number of consecutive zeros to be received
before generating the RXSTOP interrupt (IIR[2]). All the received zeros are stored in the RX FIFO. When
the register is cleared to 0, this feature is deactivated and always in reception state, which is disabled by
setting the ACREG[5] bit to 1.
The BOF length register (EBLR) is shown in
and described in
NOTE:
If the RX_STOP interrupt occurs before a byte boundary, the remaining bits of the last byte
are filled with zeros and then passed into the RX FIFO.
Figure 19-62. BOF Length Register (EBLR)
15
8
7
0
Reserved
EBLR
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 19-60. BOF Length Register (EBLR) Field Descriptions
Bit
Field
Value
Description
15-8
Reserved
0
Reserved.
7-0
EBLR
IrDA mode: This register allows definition of up to 176 xBOFs, the maximum required by IrDA
specification.
CIR mode: This register specifies the number of consecutive zeros to be received before
generating the RXSTOP interrupt (IIR[2]).
0
Feature disabled.
1h
Generate RXSTOP interrupt after receiving 1 zero bit.
...
FFh
Generate RXSTOP interrupt after receiving 255 zero bits.
3531
SPRUH73H – October 2011 – Revised April 2013
Universal Asynchronous Receiver/Transmitter (UART)
Copyright © 2011–2013, Texas Instruments Incorporated