xr16m2750 Exar Corporation, xr16m2750 Datasheet - Page 10

• Manufacturer Part Number: xr16m2750
• Description: High Performance Duart With 64-byte Fifo
• Manufacturer: Exar Corporation

XR16M2750
1.62V TO 3.63V HIGH PERFORMANCE DUART WITH 64-BYTE FIFO
The INTA and INTB interrupt output changes according to the operating mode and enhanced features setup.
Table 3 and 4
through
The M2750 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
Auto RS485
LOW = no data
HIGH = 1 byte
Mode
YES
NO
(FIFO D
T
FCR B
ABLE
T
ABLE
LOW = a byte in THR
HIGH = THR empty
LOW = a byte in THR
HIGH = transmitter empty
IT
ISABLED
F
3: INTA
-0 = 0
IGURE
4: INTA
(FIFO D
FCR B
)
4. T
AND
AND
22-47 pF
IT
ISABLED
YPICAL OSCILLATOR CONNECTIONS
XTAL1
INTB P
-0 = 0
C1
LOW = FIFO below trigger level
HIGH = FIFO above trigger level
INTB P
500 ΚΩ − 1 ΜΩ
)
INS
R2
10
IN
22-47 pF
XTAL2
O
C2
O
Y1
PERATION FOR
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
PERATION
1.8432 MHz
(Optional)
0-120 Ω
24 MHz
R1
to
F
FCR B
OR
(FIFO E
FCR B
T
RANSMITTER
R
ECEIVER
IT
-0 = 1 (FIFO E
IT
NABLED
-0 = 1
)
11.”
NABLED
)
Figures 17
REV. 1.0.0