LPC1114FHN33/203,5 NXP Semiconductors, LPC1114FHN33/203,5 Datasheet - Page 200

• Manufacturer Part Number: LPC1114FHN33/203,5
• Description: ARM Microcontrollers - MCU Cortex-M0 32 kB Fl 8 kB SRAM
• Manufacturer: NXP Semiconductors

Specifications of LPC1114FHN33/203,5

• Rohs: yes
• Core: ARM Cortex M0
• Processor Series: LPC1114
• Data Bus Width: 32 bit
• Maximum Clock Frequency: 50 MHz
• Program Memory Size: 32 KB
• Data Ram Size: 8 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 1.8 V to 3.6 V
• Operating Temperature Range: - 65 C to + 150 C
• Package / Case: HVQFN-33
• Mounting Style: SMD/SMT
• Factory Pack Quantity: 260

NXP Semiconductors
UM10398
User manual
13.5.8.1.1 Auto-RTS
13.5.8.1 Auto-flow control
Table 193. UART0 Modem Control Register (U0MCR - address 0x4000 8010) bit description
If auto-RTS mode is enabled the UART‘s receiver FIFO hardware controls the RTS output
of the UART. If the auto-CTS mode is enabled the UART‘s U0TSR hardware will only start
transmitting if the CTS input signal is asserted.
The auto-RTS function is enabled by setting the RTSen bit. Auto-RTS data flow control
originates in the U0RBR module and is linked to the programmed receiver FIFO trigger
level. If auto-RTS is enabled, the data-flow is controlled as follows:
When the receiver FIFO level reaches the programmed trigger level, RTS is deasserted
(to a high value). It is possible that the sending UART sends an additional byte after the
trigger level is reached (assuming the sending UART has another byte to send) because it
might not recognize the deassertion of RTS until after it has begun sending the additional
byte. RTS is automatically reasserted (to a low value) once the receiver FIFO has reached
the previous trigger level. The reassertion of RTS signals the sending UART to continue
transmitting data.
If Auto-RTS mode is disabled, the RTSen bit controls the RTS output of the UART. If
Auto-RTS mode is enabled, hardware controls the RTS output, and the actual value of
RTS will be copied in the RTS Control bit of the UART. As long as Auto-RTS is enabled,
the value of the RTS Control bit is read-only for software.
Bit
4
5
6
7
31:8 -
Symbol
LMS
-
RTSEN
CTSEN
All information provided in this document is subject to legal disclaimers.
Value Description
0
1
0
1
0
1
-
Rev. 12 — 24 September 2012
Loopback Mode Select. The modem loopback mode provides a
mechanism to perform diagnostic loopback testing. Serial data
from the transmitter is connected internally to serial input of the
receiver. Input pin, RXD, has no effect on loopback and output
pin, TXD is held in marking state. The four modem inputs (CTS,
DSR, RI and DCD) are disconnected externally. Externally, the
modem outputs (RTS, DTR) are set inactive. Internally, the four
modem outputs are connected to the four modem inputs. As a
result of these connections, the upper four bits of the U0MSR will
be driven by the lower four bits of the U0MCR rather than the four
modem inputs in normal mode. This permits modem status
interrupts to be generated in loopback mode by writing the lower
four bits of U0MCR.
Disable modem loopback mode.
Enable modem loopback mode.
Reserved, user software should not write ones to reserved bits.
The value read from a reserved bit is not defined.
RTS flow control
Disable auto-rts flow control.
Enable auto-rts flow control.
CTS flow control
Disable auto-cts flow control.
Enable auto-cts flow control.
Reserved
Chapter 13: LPC111x/LPC11Cxx UART
UM10398
© NXP B.V. 2012. All rights reserved.
200 of 538
Reset
value
0
0
0
0
-