XR16C850 Ver la hoja de datos (PDF) - Exar Corporation
Número de pieza
componentes Descripción
Lista de partido
XR16C850 Datasheet PDF : 55 Pages
| |||
XR16C850
SYMBOL DESCRIPTION
Symbol
S3 / -OP2
SEL
TC
-TXRDY
VCC
XTAL1
XTAL2
-CD
-CTS
Pin
Signal
40 44 48 52 type
Pin Description
31 35 31 34 I/O Select-3 or User Defined Output-2 (dual function
with internal pull-up) - When PC mode is selected,
S3 is used in conjunction with S1, S2 and A3-A9 to
select one of the PC COM port addresses. In the
STD mode this pin provides the user a general
purpose output. See bit-3 modem control register
(MCR bit-3).
-
34 36 39
I
Select Mode (internal pull-up) - The PC mode is
selected by a logic 0 (GND) on this pin and STD
mode is selected when this pin is a logic 1 (left open
or tied to VCC). This pin is not available on the 40 pin
PDIP packages which operate in the STD mode
only.
-
-
-
13
I
Terminal Count Bit (internal pull-up). A high pulse
indicates terminal count for any DMA channel is
reached. Connect this pin to GND when not used.
(See IRQC)
40 44 42 45 Pwr Power Supply Input.
16 18 14 15
I
Crystal or External Clock Input - Functions as a
crystal input or as an external clock input. A crystal
can be connected between this pin and XTAL2 to
form an internal oscillator circuit. An external 1 MΩ
resistor is required between the XTAL1 and XTAL2
pins (see figure 9). Alternatively, an external clock
can be connected to this pin to provide custom data
rates (Programming Baud Rate Generator section).
17
19
15
16
O Output of the Crystal Oscillator or Buffered Clock -
(See also XTAL1). Crystal oscillator output or buff-
ered clock output.
38 42 40 43
I
Carrier Detect (active low) - A logic 0 on this pin
indicates that a carrier has been detected by the
modem.
36 40 38 41
I
Clear to Send (active low) - A logic 0 on the -CTS pin
indicates the modem or data set is ready to accept
transmit data from the 850. Status can be tested by
Rev. 1.20
10
Share Link: 