ADSP-BF537 Blackfin Processor Hardware Reference
13-25
UART Port Controllers
The
PE
bit indicates that the received parity bit does not match the
expected value. The
PE
bit is set simultaneously with the
DR
bit. The
PE
bit
cleared when the
LSR
register is read. Invalid parity bits can be simulated
by setting the
FPE
bit in the
UARTx_GCTL
register.
The
FE
bit indicates that the first stop bit has been sampled low. It is
cleared by hardware when the
UARTx_RBR
register is read. Invalid stop bits
can be simulated by setting the
FFE
bit in the
UARTx_GCTL
register.
The
BI
bit indicates that the first stop bit has been sampled low and the
entire data word, including parity bit, consists of low bits only. It is
cleared by hardware when the
UARTx_RBR
register is read.
L
Because of the destructive nature of these read operations, special
care should be taken. For more information, see the Memory chap-
ter of the ADSP-BF53x/BF56x Blackfin Processor Programming
Reference.
The
THRE
bit indicates that the UART transmit channel is ready for new
data and software can write to
UARTx_THR
. Writes to
UARTx_THR
clear the
THRE
bit. It is set again when data is passed from
UARTx_THR
to the internal
TSR
register.
The
TEMT
bit indicates that both the
UARTx_THR
register and the internal
TSR
register are empty. In this case the program is permitted to write to
the
UARTx_THR
register twice without losing data. The
TEMT
bit can also be
used as indicator that pending UART transmission has been completed.
At that time it is safe to disable the
UCEN
bit or to three-state the off-chip
line driver.
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...