LPC1837FET256,551 NXP Semiconductors, LPC1837FET256,551 Datasheet - Page 782

• Manufacturer Part Number: LPC1837FET256,551
• Description: Microcontrollers (MCU) 32BIT ARM CORTEX-M3 MCU 136KB SRAM
• Manufacturer: NXP Semiconductors
• Series: LPC18xxr

Specifications of LPC1837FET256,551

• Core: ARM Cortex M3
• Core Processor: ARM® Cortex-M3™
• Core Size: 32-Bit
• Speed: 150MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, Microwire, SD/MMC, SPI, SSI, SSP, UART/USART, USB OTG
• Peripherals: Brown-out Detect/Reset, DMA, I²S, Motor Control PWM, POR, PWM, WDT
• Number Of I /o: 80
• Program Memory Size: 1MB (1M x 8)
• Program Memory Type: FLASH
• Eeprom Size: -
• Ram Size: 136K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 16x10b; D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 256-LBGA
• Lead Free Status / Rohs Status: Details
• Other names: 935293795551

NXP Semiconductors
<Document ID>
User manual
34.7.2.5 SPI format with CPOL = 1,CPHA = 1
If the SSP is enabled and there is valid data within the transmit FIFO, the start of
transmission is signified by the SSEL master signal being driven LOW, which causes
slave data to be immediately transferred onto the MISO line of the master. Master’s MOSI
pin is enabled.
One half period later, valid master data is transferred to the MOSI line. Now that both the
master and slave data have been set, the SCK master clock pin becomes LOW after one
further half SCK period. This means that data is captured on the falling edges and be
propagated on the rising edges of the SCK signal.
In the case of a single word transmission, after all bits of the data word are transferred, the
SSEL line is returned to its idle HIGH state one SCK period after the last bit has been
captured.
However, in the case of continuous back-to-back transmissions, the SSEL signal must be
pulsed HIGH between each data word transfer. This is because the slave select pin
freezes the data in its serial peripheral register and does not allow it to be altered if the
CPHA bit is logic zero. Therefore the master device must raise the SSEL pin of the slave
device between each data transfer to enable the serial peripheral data write. On
completion of the continuous transfer, the SSEL pin is returned to its idle state one SCK
period after the last bit has been captured.
The transfer signal sequence for SPI format with CPOL = 1, CPHA = 1 is shown in
Figure
In this configuration, during idle periods:
If the SSP is enabled and there is valid data within the transmit FIFO, the start of
transmission is signified by the SSEL master signal being driven LOW. Master’s MOSI is
enabled. After a further one half SCK period, both master and slave data are enabled onto
their respective transmission lines. At the same time, the SCK is enabled with a falling
edge transition. Data is then captured on the rising edges and propagated on the falling
edges of the SCK signal.
Fig 104. SPI Frame Format with CPOL = 1 and CPHA = 1
•
•
•
The CLK signal is forced HIGH.
SSEL is forced HIGH.
The transmit MOSI/MISO pad is in high impedance.
104, which covers both single and continuous transfers.
All information provided in this document is subject to legal disclaimers.
SSEL
MOSI
MISO
SCK
Rev. 00.13 — 20 July 2011
Q
MSB
MSB
4 to 16 bits
LSB
LSB
Chapter 34: LPC18xx SSP0/1
Q
UM10430
© NXP B.V. 2011. All rights reserved.
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