Serial Management Controllers (SMCs)
MPC885 PowerQUICC Family Reference Manual, Rev. 2
Freescale Semiconductor
29-15
Data length represents the number of octets the CP writes into the buffer. After data is received in the
buffer, the CP only writes the data length once as the BD closes. Note that the memory allocated for this
buffer should be no smaller than MRBLR. The Rx buffer pointer points to the first location of the buffer
and must be even. The buffer can be in internal or external memory.
Figure 29-7
shows an example of how
RxBDs are used in receiving 10 characters, an idle period, and five characters (one with a framing error).
The example assumes that MRBLR = 8.
10
BR
Buffer closed on reception of break. Set when the buffer closes because a break sequence was
received. The CP writes BR after the received data is in the buffer.
11
FR
Framing error. Set when a character with a framing error is received and located in the last byte of
this buffer. A framing error is a character with no stop bit. A new receive buffer is used to receive
additional data. The CP writes FR after the received data is in the buffer.
12
PR
Parity error. Set when a character with a parity error is received in the last byte of the buffer. A new
buffer is used for additional data. The CP writes PR after received data is in the buffer.
13
—
Reserved, should be cleared
14
OV
Overrun. Set when a receiver overrun occurs during reception. The CP writes OV after the received
data is in the buffer.
15
—
Reserved, should be cleared
Table 29-8. SMC UART RxBD Status and Control Field Descriptions (continued)
Bit
Name
Description
Summary of Contents for PowerQUICC MPC870
Page 98: ...MPC885 PowerQUICC Family Reference Manual Rev 2 I 4 Freescale Semiconductor ...
Page 118: ...MPC885 Overview MPC885 PowerQUICC Family Reference Manual Rev 2 1 20 Freescale Semiconductor ...
Page 158: ...The MPC8xx Core MPC885 PowerQUICC Family Reference Manual Rev 2 3 18 Freescale Semiconductor ...
Page 288: ...MPC885 PowerQUICC Family Reference Manual Rev 2 III 4 Freescale Semiconductor ...
Page 554: ...MPC885 PowerQUICC Family Reference Manual Rev 2 V 6 Freescale Semiconductor ...
Page 1090: ...UTOPIA Interface MPC885 PowerQUICC Family Reference Manual Rev 2 43 8 Freescale Semiconductor ...
Page 1312: ...Byte Ordering MPC885 PowerQUICC Family Reference Manual Rev 2 A 8 Freescale Semiconductor ...
Page 1336: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 16 Freescale Semiconductor ...
Page 1358: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 38 Freescale Semiconductor ...
Page 1370: ...MPC880 MPC885 PowerQUICC Family Reference Manual Rev 2 E 4 Freescale Semiconductor ...
Page 1386: ...Revision History MPC885 PowerQUICC Family Reference Manual Rev 2 I 2 Freescale Semiconductor ...