NS7520B-1-I46 Digi International, NS7520B-1-I46 Datasheet - Page 315

• 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

Clock speed errata using PLL in boundary scan mode
NS7520 errata
Jan 17, 2006
This section lists the known errata for the NS7520, describing each problem and, in
most cases, providing a workaround.
Refer to Figure 5 “PLL Mode hardware configuration" in Chapter 5 for more
information.
Software workarounds
Modify these bits in Serial Channel Control register A:
–
–
–
Non-DMA mode: Because FIFO can hold up to eight lines of 4 bytes each, the
maximum skid rate will be 32 characters.
To reduce the maximum skid rate to eight characters, the software is
changed to write 1 byte in each line.
In DMA mode, the skid rate can be up to the number of bytes transmitted in
1 tick.
The serial monitor thread is changed to handle the missing CTS interrupt.
UART CTS-related transmit data errors
A problem occurs when the CTS flow control signal is de-asserted during the
BCLK that begins processing a new character. This problem causes the
previous character to be re-transmitted instead of getting the next character
from the transmit FIFO.
Set the CTSTX bit (bit 23) to 0 to disable hardware-controlled CTSTX.
Set the ERXCTS bit (bit 4) to enable the software CTS signal change
interrupt.
Update the serial transmit ISR to handle the CTS signal change.
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