SH7619 Datasheet, PDF (355/836 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7619 Series

Section 12 Ethernet Controller Direct Memory Access Controller (E-DMAC)
Transmission task
1.
Make initial settings for the timer.
2. Prepare multiple transmit descriptors.
Transmission starts.
After setting the transmit descriptor,
3. _{set the TR bit in EDTRR to 1.}
Next transmission task
No
generated?
Yes
End
Read the TACT bit of the
corresponding transmit descriptor.
No
4.
TACT = 0?
Yes
5.
5. _{After setting the corresponding transmit}
8. descriptor, set the TR bit in EDTRR to 1.
6.
i = 0;
Start the timer.
Specified constant
period elapsed?
*¹
No
Yes
7.
Stop the timer.
Read the TACT bit of
the corresponding
transmit descriptor.
No
8.
TACT = 0?
Yes
i++;
9.
i >= n? ^*2
No
Yes
Issue a software reset to
initialize the EtherC and
E-DMAC modules.
Make initial settings of the
EtherC and E-DMAC modules.
Initialize the transmit/receive
descriptors and transmit/receive
buffers.
Notes: 1. The specified constant period is the timeout period mentioned in section 12.4.1, Usage Notes on SH-Ether EtherC/E-DMAC Status Register
(EESR).
2. Set n with reference to the maximum specified time values in table 12.2.
: Processing added as the countermeasure for the problem
Figure 12.12 Processing Transmission without Handling of the TC Interrupt
Rev. 5.00 Mar. 15, 2007 Page 317 of 794
REJ09B0237-0500