HD6417615 Hitachi Semiconductor, HD6417615 Datasheet - Page 463

• Manufacturer Part Number: HD6417615
• Description: Hardware Manual
• Manufacturer: Hitachi Semiconductor

The E-DMAC continues reading descriptors and transmitting frames as long as the setting of the
TACT bit in the read descriptors is “active.” When a descriptor with an “inactive” TACT bit is
read, the E-DMAC resets the transmit request bit (TR) in the transmit register and ends transmit
processing (EDTRR).
448
Transmission flowchart
SH7615 + memory
EtherC/E-DMAC
Descriptor and
buffer setting
initialization
transmit
Transmit data transfer
Transmit data transfer
Descriptor write-back
Transmit directive
Descriptor read
Descriptor write-back
Descriptor read
Figure 10.4 Sample Transmission Flowchart
E-DMAC
Transmission
completed
Transmission MFIFO
EtherC
Frame transmission
Ethernet