What Is The Relationship Between Cell Transmission Scheduling And Dma Operations; Does The Host Cpu Have To Set The A Bit Of The Scheduler Register - NEC mPD98409 Q&A

CHAPTER 6 TRANSMISSION SCHEDULER
Q.6.6

What is the relationship between cell transmission scheduling and DMA operations?

A.6.6
The µ PD98409 determines the cell to be transmitted every 24 clocks by using the scheduler. After the cell to be
transmitted has been determined, a DMA operation to read the cell data is executed. If the transmit FIFO has
become full, the DMA operation to read cell data is stopped.
Reference: µ PD98409 User's Manual 5.4.4 (7) Algorithm operation
Q.6.7

Does the host CPU have to set the A bit of the scheduler register?

A.6.7
The A bit of the scheduler register is managed or changed by the µ PD98409. It is not necessary for the host CPU
to rewrite this bit. The host CPU must set the A bit only when a shaper is used as an unassigned cell generator.
Reference: µ PD98409 User's Manual 5.4.4 (4) Scheduler register
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