ADSP-BF537 Blackfin Processor Hardware Reference
8-43
Ethernet MAC
RX Frame Status Register Operation at Startup and Shutdown
After the
RE
bit in the
EMAC_OPMODE
register is cleared, the RX current
frame status register, the RX sticky frame status register, and the RX frame
status interrupt enable register hold their last state. Of course, the two
writable registers can still be written.
In order to not confuse status from old and new frames, the RX current
frame status register and the RX sticky frame status register are automati-
cally cleared at a 0-to-1 transition of the
RE
bit. The RX frame status
interrupt enable register is not cleared when the
RE
bit transitions from 0
to 1. It changes state only when written.
All three of these registers are cleared at system reset.
TX Frame Status Register Operation at Startup and Shutdown
After the
TE
bit in the
EMAC_OPMODE
register is cleared, the TX current
frame status register, the TX sticky frame status register, and the TX frame
status interrupt enable register hold their last state. Of course, the two
writable registers can still be written.
In order to not confuse status from old and new frames, the TX current
frame status register and the TX sticky frame status register are automati-
cally cleared at a 0-to-1 transition of the
TE
bit. The TX frame status
interrupt enable register is not cleared when the
TE
bit transitions from 0
to 1. It changes state only when written.
All three of these registers are cleared at system reset.
MAC Management Counters
The Blackfin Ethernet MAC provides a comprehensive set of 32-bit
read-only MAC management counters, 24 for receive and 23 for transmit,
in accordance with the “Layer Management for DTEs” specification in
IEEE 802.3 Sec. 30.3. When enabled by setting the
MMCE
bit in the
EMAC_MMC_CTL
register, the counters are updated automatically at the
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...