5 Serial Ports
5 – 40
• SPORT0 transmit autobuffer—highest priority (not on ADSP-2105)
• SPORT0 receive autobuffer (not on ADSP-2105)
• SPORT1 transmit autobuffer
• SPORT1 receive autobuffer
• Unmasked pending interrupts in priority order
5.13.8 Interrupt & Autobuffer Service Example
Figure 5.35 shows the execution of a serial port interrupt based on a
request that meets the setup and hold time requirements. This example is
the same for a receive or a transmit interrupt request.
An additional latency cycle is consumed due to the fetching of the first
instruction of the interrupt routine. The interrupt can only be serviced on
an instruction cycle boundary. The above example (in Figure 5.35)
assumes all instructions are completed in one processor cycle. Figure 5.36
shows the result of an autobuffer request that meets the setup and hold
requirements.
Request
CLKOUT
EXEC
A
B
C
AUTOBUFFER
Sync Delay
Expand The Receive Register
Do The Autobuffer Transfer
D
COMPAND
EXPAND RX
Continue Main Program
Figure 5.37 Receive Companding Example