sc16c850iet NXP Semiconductors, sc16c850iet Datasheet - Page 16

• Manufacturer Part Number: sc16c850iet
• Description: Sc16c850 2.5 V To 3.3 V Uart, 5 Mbit/s Max. With 128-byte Fifos, Infrared Irda , And 16 Mode Or 68 Mode Parallel Bus Interface
• Manufacturer: NXP Semiconductors

NXP Semiconductors
SC16C850_1
Product data sheet
6.10 Loopback mode
Table 7.
The internal loopback capability allows on-board diagnostics. In the Loopback mode, the
normal modem interface pins are disconnected and reconfigured for loopback internally
(see
In the Loopback mode, the transmitter output (TX) and the receiver input (RX) are
disconnected from their associated interface pins, and instead are connected together
internally. The CTS, DSR, CD, and RI are disconnected from their normal modem control
input pins, and instead are connected internally to RTS, DTR, MCR[3] (OP2) and MCR[2]
(OP1). Loopback test data is entered into the transmit holding register via the user data
bus interface, D[7:0]. The transmit UART serializes the data and passes the serial data to
the receive UART via the internal loopback connection. The receive UART converts the
serial data back into parallel data that is then made available at the user data interface
D[7:0]. The user optionally compares the received data to the initial transmitted data for
verifying error-free operation of the UART TX/RX circuits.
In this mode, the interrupt pin is 3-stated, therefore, the software must use the polling
method (see
Output
baud rate
(bit/s)
38.4 k
57.6 k
115.2 k
Figure
Baud rate generator programming table using a 1.8432 MHz clock when
MCR[7] = 0 and CLKPRES[3:0] = 0
9). MCR[3:0] register bits are used for controlling loopback diagnostic testing.
Section
Output
16 clock divisor
(decimal)
3
2
1
2.5 V to 3.3 V UART with 128-byte FIFOs and IrDA encoder/decoder
7.2.2) to send and receive data.
Rev. 01 — 10 January 2008
Output
16 clock divisor
(hexadecimal)
03
02
01
…continued
DLM
program value
(hexadecimal)
00
00
00
SC16C850
© NXP B.V. 2008. All rights reserved.
DLL
program value
(hexadecimal)
03
02
01
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