NS16C2752TVSX/NOPB National Semiconductor, NS16C2752TVSX/NOPB Datasheet - Page 26

• Manufacturer Part Number: NS16C2752TVSX/NOPB
• Description: IC UART DUAL 64BYTE 48-TQFP
• Manufacturer: National Semiconductor

Specifications of NS16C2752TVSX/NOPB

• Features: Programmable
• Number Of Channels: 2, DUART
• Fifo's: 64 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

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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