UART/IrDA Control and Status Registers
12-77
UART Devices
The received frame length registers (RXFLL and RXFLH) hold the 12-bit
receive maximum frame length. RXFLL holds the least significant bits, and
RXFLH holds the most significant bits. If the intended maximum receive frame
length is n bytes, then program RXFLL and RXFLH to n + 3 in SIR mode (+3
is due to frame format with CRC and stop flag).
In terms of the IrDA frame format (see Figure 12–14), the value stored in the
RXFLH/RXFLL registers is the byte length from A to EOF.
Table 12–76. Received Frame Length Low Register (RXFLL)
Bit
Name
Function
R/W
Reset
Value
7–0
RXFLL
LSB register used to specify the frame length in
reception
W
00000000
Offset Address (hex): 0x0D x Start Address
Table 12–77. Received Frame Length High Register (RXFLH)
Bit
Name
Function
R/W
Reset
Value
7–4
–
Reserved
W
0000
3–0
RXFLH
MSB register used to specify the frame length in
reception
W
0000