LPC1342FHN33,551 NXP Semiconductors, LPC1342FHN33,551 Datasheet - Page 47

• Manufacturer Part Number: LPC1342FHN33,551
• Description: IC MCU 32BIT 16KB FLASH 33HVQFN
• Manufacturer: NXP Semiconductors
• Series: LPC13xxr

Specifications of LPC1342FHN33,551

• Program Memory Type: FLASH
• Program Memory Size: 16KB (16K x 8)
• Package / Case: 33-VQFN Exposed Pad, 33-HVQFN, 33-SQFN, 33-DHVQFN
• Core Processor: ARM® Cortex-M3™
• Core Size: 32-Bit
• Speed: 72MHz
• Connectivity: I²C, Microwire, SPI, SSI, SSP, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, WDT
• Number Of I /o: 28
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: LPC13
• Core: ARM Cortex M3
• Data Bus Width: 32 bit
• Data Ram Size: 4 KB
• Interface Type: I2C, UART
• Maximum Clock Frequency: 72 MHz
• Number Of Programmable I/os: 28
• Number Of Timers: 4
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: MDK-ARM, RL-ARM, ULINK2
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Package: 33HVQFN EP
• Device Core: ARM Cortex M3
• Family Name: LPC1000
• Maximum Speed: 72 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 622-1005 - USB IN-CIRCUIT PROG ARM7 LPC2K
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 568-4946; 935289656551

NXP Semiconductors
UM10375
User manual
3.10.1 Lock detector
3.10.2 Power-down control
3.10.3 Divider ratio programming
The block diagram of this PLL is shown in
to 25 MHz. The input clock is fed directly to the Phase-Frequency Detector (PFD). This
block compares the phase and frequency of its inputs, and generates a control signal
when phase and/ or frequency do not match. The loop filter filters these control signals
and drives the current controlled oscillator (CCO), which generates the main clock and
optionally two additional phases. The CCO frequency range is 156 MHz to
320 MHz.These clocks are either divided by 2×P by the programmable post divider to
create the output clock(s), or are sent directly to the output(s). The main output clock is
then divided by M by the programmable feedback divider to generate the feedback clock.
The output signal of the phase-frequency detector is also monitored by the lock detector,
to signal when the PLL has locked on to the input clock.
The lock detector measures the phase difference between the rising edges of the input
and feedback clocks. Only when this difference is smaller than the so called “lock
criterion” for more than eight consecutive input clock periods, the lock output switches
from low to high. A single too large phase difference immediately resets the counter and
causes the lock signal to drop (if it was high). Requiring eight phase measurements in a
row to be below a certain figure ensures that the lock detector will not indicate lock until
both the phase and frequency of the input and feedback clocks are very well aligned. This
effectively prevents false lock indications, and thus ensures a glitch free lock signal.
To reduce the power consumption when the PLL clock is not needed, a Power-down
mode has been incorporated. This mode is enabled by setting the SYSPLL_PD (or
USBPLL_PD) bits to one in the Power-down configuration register
mode, the internal current reference will be turned off, the oscillator and the
phase-frequency detector will be stopped and the dividers will enter a reset state. While in
Power-down mode, the lock output will be low to indicate that the PLL is not in lock. When
the Power-down mode is terminated by setting the SYSPLL_PD (or USBPLL_PD) bits to
zero, the PLL will resume its normal operation and will make the lock signal high once it
has regained lock on the input clock.
Post divider
The division ratio of the post divider is controlled by the PSEL bits. The division ratio is two
times the value of P selected by PSEL bits as shown in
guarantees an output clock with a 50% duty cycle.
Feedback divider
The feedback divider’s division ratio is controlled by the MSEL bits. The division ratio
between the PLL’s output clock and the input clock is the decimal value on MSEL bits plus
one, as specified in
Changing the divider values
Changing the divider ratio while the PLL is running is not recommended. As there is no
way to synchronize the change of the MSEL and PSEL values with the dividers, the risk
exists that the counter will read in an undefined value, which could lead to unwanted
All information provided in this document is subject to legal disclaimers.
Table 8
Rev. 2 — 7 July 2010
and
Table
10.
Figure
Chapter 3: LPC13xx System configuration
4. The input frequency range is 10 MHz
Table 8
and
(Table
Table
UM10375
© NXP B.V. 2010. All rights reserved.
52). In this
10. This
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