NS7520B-1-I46 Digi International, NS7520B-1-I46 Datasheet - Page 264

• 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

Serial Channel 1, 2 Receive Character Gap Timer
2 5 2
S e r i a l C h a n n e l r e g i s t e r s
Table 92: Serial Channel Receive Buffer Gap Timer bit definition
Address: FFD0 0018 / 58
The receive character gap timer closes out a receive serial data buffer due to a gap
between characters. The timer is reset when a character is received. When the timer
reaches its programmed threshold, the receive data buffer is closed.
If the serial channel is configured to operate in DMA mode, the DMA channel is
signaled to close the buffer and start a new buffer. If the serial channel is configured
in interrupt mode, the expiration of the timer causes an interrupt to be generated.
The receive character timer uses F
The receive character timer is configured with a 10-bit programmable counter. The
effective buffer timer value is defined by this equation:
TIMEOUT = [512 * (CT + 10)] / F
D14:00
Bits
R/W
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
BT
Mnemonic
XTALE
0
Reset
XTALE
and a 9-bit prescaler within the SER module.
BT timer
The required value for the receive buffer gap timer is
a function of the channel bit-rate and the maximum
receive buffer size. It is recommended that you set the
buffer gap timer to a value that is slightly larger that
the amount of time required to fill the maximum
buffer size using the channel bit-rate. Use this
equation to define the recommended buffer gap timer
value:
BT RECOMMENDED =
[(MAX_RX_BUF_SIZE * 1.10 * F
- 1
If the resulting value doesn’t fit within the range for
BT, reconsider the size of
Description
MAX_RF_BUF_SIZE
XTALE
) / (bit-rate * 512)]
.