LPC1767 NXP [NXP Semiconductors], LPC1767 Datasheet - Page 34

• Manufacturer Part Number: LPC1767
• Description: 32-bit ARM Cortex-M3 microcontroller; up to 512 kB flash and 64 kB SRAM with Ethernet, USB 2.0 Host/Device/OTG, CAN
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
LPC1769_68_67_66_65_64_4
Product data sheet
7.29.6.3 Power-down mode
7.29.6.4 Deep power-down mode
7.29.6.5 Wake-up interrupt controller
7.29.7 Peripheral power control
The Deep-sleep mode can be terminated and normal operation resumed by either a
Reset or certain specific interrupts that are able to function without clocks. Since all
dynamic operation of the chip is suspended, Deep-sleep mode reduces chip power
consumption to a very low value. Power to the flash memory is left on in Deep-sleep
mode, allowing a very quick wake-up.
On wake-up from Deep-sleep mode, the code execution and peripherals activities will
resume after 4 cycles expire if the IRC was used before entering Deep-sleep mode. If the
main external oscillator was used, the code execution will resume when 4096 cycles
expire. PLL and clock dividers need to be reconfigured accordingly.
Power-down mode does everything that Deep-sleep mode does, but also turns off the
power to the IRC oscillator and the flash memory. This saves more power but requires
waiting for resumption of flash operation before execution of code or data access in the
flash memory can be accomplished.
On the wake-up of Power-down mode, if the IRC was used before entering Power-down
mode, it will take IRC 60 μs to start-up. After this 4 IRC cycles will expire before the code
execution can then be resumed if the code was running from SRAM. In the meantime, the
flash wake-up timer then counts 4 MHz IRC clock cycles to make the 100 μs flash start-up
time. When it times out, access to the flash will be allowed. Users need to reconfigure the
PLL and clock dividers accordingly.
The Deep power-down mode can only be entered from the RTC block. In Deep
power-down mode, power is shut off to the entire chip with the exception of the RTC
module and the RESET pin.
The LPC17xx can wake up from Deep power-down mode via the RESET pin or an alarm
match event of the RTC.
The Wake-up Interrupt Controller (WIC) allows the CPU to automatically wake up from
any enabled priority interrupt that can occur while the clocks are stopped in Deep sleep,
Power-down, and Deep power-down modes.
The WIC works in connection with the Nested Vectored Interrupt Controller (NVIC). When
the CPU enters Deep sleep, Power-down, or Deep power-down mode, the NVIC sends a
mask of the current interrupt situation to the WIC.This mask includes all of the interrupts
that are both enabled and of sufficient priority to be serviced immediately. With this
information, the WIC simply notices when one of the interrupts has occurred and then it
wakes up the CPU.
The WIC eliminates the need to periodically wake up the CPU and poll the interrupts
resulting in additional power savings.
A Power Control for Peripherals feature allows individual peripherals to be turned off if
they are not needed in the application, resulting in additional power savings.
Rev. 04 — 1 February 2010
LPC1769/68/67/66/65/64
32-bit ARM Cortex-M3 microcontroller
© NXP B.V. 2010. All rights reserved.
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