NS7520B-1-I46 Digi International, NS7520B-1-I46 Datasheet - Page 156

• Manufacturer Part Number: NS7520B-1-I46
• Description: IC ARM MICROPROCESSOR 177BGA
• Manufacturer: Digi International
• Series: NET+ARM®r

Specifications of NS7520B-1-I46

• Applications: Network Processor
• Core Processor: ARM7
• Program Memory Type: External Program Memory
• Controller Series: -
• Ram Size: External
• Interface: EBI/EMI, Ethernet, DMA, SPI, UART
• Number Of I /o: 16
• Voltage - Supply: 1.4 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 177-LFBGA
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

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E t h e r n e t t r a n s f e r c o n s i d e r a t i o n s
Ethernet transfer considerations
Table 51: DMA Status/Interrupt Enable register bit definition
Under heavy load, the Ethernet transmitter can, on rare occasions, fail to recover
from aborted transmits caused by events such as late collisions and transmit
underruns. This situation occurs under the following conditions:
The transmit operation will not proceed until the condition is corrected.
D20
D19
D18
D17
D16
D15
D[14:00]
Bits
TXCOLC or TXAUR bits in the Ethernet Transmitter Status register are set
to 1.
Full bit in the current DMA buffer descriptor is set to 1.
Status field in the DMA buffer descriptor is set to 0.
R/W
R
R
R
R
N/A
R
Access
N S 7 5 2 0 H a r d w a r e R e f e r e n c e , R e v G 9 / 2 0 0 7
CAIE
WRAP
IDONE
LAST
FULL
Reserved
BLEN
Mnemonic
0
0
0
0
0
N/A
0
Reset
Channel abort interrupt enable
Use these bits to enable interrupts to be generated when the
associated IP bits are set.
Last descriptor in descriptor list
Interrupt on done
Last buffer descriptor in current data frame
Buffer full indicator
N/A
Remaining byte transfer count
Use these bits for debugging purposes only. The bits serve
no useful purpose to the firmware device driver.
Description
DMA) operations.
outbound (read DMA) operations.
be used at the same time.
In general, the NCIE bit is used for inbound (write
The DMA buffer descriptor I bit should be used for
The ECIE and CAIE bits should always be enabled.
NCIE and the DMA buffer descriptor I bit should not