xr16m2550 Exar Corporation, xr16m2550 Datasheet - Page 9

• Manufacturer Part Number: xr16m2550
• Description: High Performance Low Voltage Duart With 16-byte Fifo
• Manufacturer: Exar Corporation

REV. 1.0.2
The INTA and INTB interrupt output changes according to the operating mode and enhanced features setup.
Table 3 and 4
through
The M2550 includes an on-chip oscillator (XTAL1 and XTAL2) to produce a clock for both UART sections in the
device. The CPU data bus does not require this clock for bus operation. The crystal oscillator provides a
system clock to the Baud Rate Generators (BRG) section found in each of the UART. XTAL1 is the input to the
oscillator or external clock buffer input with XTAL2 pin being the output. For programming details, see
““Section 2.9, Programmable Baud Rate Generator with Fractional Divisor” on page
2.7
2.8
INTA/B Pin
INTA/B Pin
INTA/B Pin
INTA and INTB Outputs
Crystal Oscillator or External Clock Input
22.
summarize the operating behavior for the transmitter and receiver. Also see
LOW = a byte in THR
HIGH = THR empty
LOW = a byte in THR
HIGH = transmitter empty
LOW = no data
HIGH = 1 byte
T
(FIFO D
(FIFO D
FCR B
ABLE
FCR B
T
ABLE
F
3: INTA
IT
ISABLED
IT
ISABLED
IGURE
-0 = 0
-0 = 0
4: INTA
HIGH PERFORMANCE LOW VOLTAGE DUART WITH 16-BYTE FIFO
)
4. T
)
AND
AND
22-47 pF
YPICAL OSCILLATOR CONNECTIONS
XTAL1
INTB P
C1
INTB P
LOW = FIFO above trigger level
HIGH = FIFO below trigger level or FIFO empty
LOW = FIFO above trigger level
HIGH = FIFO below trigger level or transmitter empty
LOW = FIFO below trigger level
HIGH = FIFO above trigger level
500 ΚΩ − 1 ΜΩ
INS
R2
IN
22-47 pF
9
XTAL2
O
C2
O
Y1
PERATION FOR
PERATION
1.8432 MHz
(Optional)
0-120 Ω
24 MHz
R1
to
FCR B
F
OR
IT
(FIFO E
T
FCR B
-0 = 1 (FIFO E
RANSMITTER
R
ECEIVER
IT
NABLED
-0 = 1
NABLED
)
10.”
)
XR16M2550
Figures 17