RapidIO Doorbell
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
16-81
16.4.3
Outbound Doorbell Controller
The outbound doorbell controller generates doorbells. Software initializes all parameters in the
necessary registers to start the doorbell transmission. The doorbell transfer starts when the
doorbell start bit, DUS, in the Outbound Doorbell Mode Register (ODMR) transitions from 0 to 1
(see Table 16-119, ODMR Field Descriptions, on page 16-187) and the doorbell controller is not
busy. Software should program all appropriate registers before setting ODMR[DUS].
Software can interact with the doorbell controller in many ways. One example method for
generating a doorbell is as follows:
1.
Poll the status register doorbell unit busy bit, ODSR[DUB], to ensure that the outbox is
not busy (see Table 16-120, ODSR Field Descriptions, on page 16-188).
2.
Clear the following ODSR status bits:
•
MER
•
RETE
•
PRT
•
EODI]
3.
Initialize the following registers:
•
Destination port (ODDPR; see page 16-189)
•
Destination attributes (ODDATR; see page 16-190)
•
Retry error threshold (ODRETCR; see page 16-191)
4.
To start the doorbell transfer, clear and then set the doorbell start bit, ODMR[DUS].
5.
ODSR[DUB] is set when ODMR[DUS] transitions from 0 to 1 to indicate that the
doorbell transfer is in progress.
6.
The outbound doorbell controller sends the doorbell.
7.
The outbound doorbell controller clears the ODSR[DUB] bit after the doorbell
operation completes. A doorbell completes when one of the following events occurs:
•
Done response received.
•
Error response received.
•
Packet response time-out.
•
Retry limit exceeded.
8.
The outbound doorbell interrupt is generated if the end of doorbell outbound doorbell
interrupt event is enabled (ODDATR[EODIE]).
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...