NS16C2552TVSX/NOPB National Semiconductor, NS16C2552TVSX/NOPB Datasheet - Page 26
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NS16C2552TVSX/NOPB
Manufacturer Part Number
NS16C2552TVSX/NOPB
Description
IC UART DUAL 16BYTE 48-TQFP
Manufacturer
National Semiconductor
Datasheet
1.NS16C2552TVSXNOPB.pdf
(44 pages)
Specifications of NS16C2552TVSX/NOPB
Features
Programmable
Number Of Channels
2, DUART
Fifo's
16 Byte
Voltage - Supply
2.97 V ~ 5.5 V
With Auto Flow Control
Yes
With Irda Encoder/decoder
Yes
With Modem Control
Yes
Mounting Type
Surface Mount
Package / Case
48-VFQFP
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
NS16C2552TVSX
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
NS16C2552TVSX/NOPB
Manufacturer:
Texas Instruments
Quantity:
10 000
www.national.com
6.15 SOFTWARE FLOW CONTROL REGISTERS (SFR)
The following four registers are used as programmable soft-
ware flow control characters.
7.0 Operation and Configuration
7.1 CLOCK INPUT
The NS16C2552/2752 has an on-chip oscillator that accepts
standard crystal with parallel resonant and fundamental fre-
quency. The generated clock is supplied to both UART chan-
nels with the capability range from DC to 24 MHz. The
frequency of the clock oscillator is divided by 16 internally,
combined with an on-chip programmable clock divider pro-
viding the baud rate for data transmission. The divisor is 16-
bit with MSB byte in DLM and LSB byte in DLL. The divisor
calculation is shown in Section 6.11 PROGRAMMABLE
BAUD GENERATOR.
The external oscillator circuitry requires two load capacitors,
a parallel resistor, and an optional damping resistor. The os-
cillator circuitry is shown in Figure 2.
7:0
Bit
Bit
7:0
7:0
Bit
Bit
7:0
Xoff2 Data
Bit Name
Xoff1 Data
Xon2 Data
Bit Name
Xon1 Data
Bit Name
Bit Name
R/W
R/W
Def
R/W
R/W
R/W
R/W
R/W
R/W
Def
Def
0
Def
0
0
0
TABLE 21. Xon1 (0x4, LCR=0xBF)
TABLE 22. Xon2 (0x5, LCR=0xBF)
TABLE 23. Xoff1 (0x6, LCR=0xBF)
TABLE 24. Xoff2 (0x7, LCR=0xBF)
Xoff2 Data
Xon2 Data
Xoff1 Data
Xon1 Data
26
The requirement of the crystal is listed in Table 25.
Crystal Frequency Range
Crystal Type
C1 & C2, Load Capacitance
ESR
Frequency Stability 0 to 70°C
TABLE 25. Crystal Component Requirement
FIGURE 2. Crystal Oscillator Circuitry
Parameter
Description
Description
Description
Description
20204804
Parallel resonant
Fundamental
<= 24 MHz
20 - 120 Ω
10 - 22 pF
100 ppm
Value