Datasheet

LPC81XM All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 4.3 — 22 April 2014 53 of 76
NXP Semiconductors
LPC81xM
32-bit ARM Cortex-M0+ microcontroller
12.7 USART interface
The maximum USART bit rate is 1.875 Mbit/s in asynchronous mode and 10 Mbit/s in
synchronous mode slave and master mode.
Remark: USART functions can be assigned to all digital pins. The characteristics are valid
for all digital pins except the open-drain pins PIO0_10 and PIO0_11.
[1] Typical ratings are not guaranteed. The values listed are for room temperature (25 C), V
DD
= 3.3 V, typical
samples.
[2] T
cy(clk)
= U_PCLK/BRGVAL. See the LPC800 User manual UM10601.
[3] Capacitance on pin Un_SCLK C
SCLK
< 5 pF.
Table 18. USART dynamic characteristics
T
amb
=  40  C to 105  C; 1.8 V  V
DD
 3.6 V. Simulated parameters sampled at the 50 % level of
the falling or rising edge; values guaranteed by design.
Symbol Parameter Conditions Min Max Unit
T
cy(clk)
clock cycle time
[2]
100 - ns
USART master (in synchronous mode)
[3]
t
su(D)
data input set-up
time
44 - ns
t
h(D)
data input hold time 0 - ns
t
v(Q)
data output valid time - -8 ns
t
h(Q)
data output hold time -8 - ns
USART slave (in synchronous mode)
t
su(D)
data input set-up
time
5- ns
t
h(D)
data input hold time 0 - ns
t
v(Q)
data output valid time C
L
= 10 pF - 40 ns
t
h(Q)
data output hold time C
L
= 10 pF 40 - ns
Fig 33. USART timing
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