Description of Operation
8-42
ADSP-BF537 Blackfin Processor Hardware Reference
L
When the MAC DMA engine is disabled, all the MAC peripheral
requests are routed directly into the interrupt controller. This can
manifest itself at startup as spurious interrupts. The solution is to
configure the system in such a way that the DMA controller is
always enabled before the MAC peripheral.
RX/TX Frame Status Interrupt Operation
The contents of the RX current frame status register indicate the result of
the most recent frame receive operation. The register contents are updated
just after the end of the frame is received on the MII and synchronized
into the system clock domain.
The contents of the RX sticky frame status register are updated at the
same time. Each applicable bit in the RX sticky frame status register is set
if the corresponding bit in the RX current frame status register is set, oth-
erwise the bit in the RX sticky frame status register keeps its prior value.
The RX frame status interrupt enable register is continuously bitwise
ANDed with the contents of the RX sticky frame status register, and then
all of the resulting bits are ORed together to produce the RX frame status
interrupt condition. The state of the RX frame status interrupt condition
is readable in the
RXFSINT
bit of the MAC system status register. This
interrupt condition is cleared by writing 1s to all the bits in the RX sticky
frame status register for which corresponding bits are set in the RX frame
status interrupt enable register. Do not attempt to clear this interrupt con-
dition by writing a 1 to the read only
RXFSINT
bit; such a write has no
effect.
The three TX frame status registers (TX current frame status register, TX
sticky frame status register, and TX frame status interrupt enable register)
operate in a similar manner.
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 ...