LPC1114FHN33/203,5 NXP Semiconductors, LPC1114FHN33/203,5 Datasheet - Page 307

• 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
16.7.3.10.1 Reception of messages with FIFO buffers
16.7.3.10.2 Reading from a FIFO buffer
16.7.3.10 Configuration of a FIFO buffer
The actual value of NEWDAT shows whether a new message has been received since
last time this Message Object was read. The actual value of MSGLST shows whether
more than one message has been received since last time this Message Object was read.
MSGLST will not be automatically reset.
Using a Remote Frame, the CPU may request another CAN node to provide new data for
a receive object. Setting the TXRQST bit of a receive object will cause the transmission of
a Remote Frame with the receive object’s identifier. This Remote Frame triggers the other
CAN node to start the transmission of the matching Data Frame. If the matching Data
Frame is received before the Remote Frame could be transmitted, the TXRQST bit is
automatically reset.
With the exception of the EOB bit, the configuration of Receive Objects belonging to a
FIFO Buffer is the same as the configuration of a (single) Receive Object, see section
Section
To concatenate two or more Message Objects into a FIFO Buffer, the identifiers and
masks (if used) of these Message Objects have to be programmed to matching values.
Due to the implicit priority of the Message Objects, the Message Object with the lowest
number will be the first Message Object of the FIFO Buffer. The EOB bit of all Message
Objects of a FIFO Buffer except the last have to be programmed to zero. The EOB bits of
the last Message Object of a FIFO Buffer is set to one, configuring it as the End of the
Block.
Received messages with identifiers matching to a FIFO Buffer are stored into a Message
Object of this FIFO Buffer starting with the Message Object with the lowest message
number.
When a message is stored into a Message Object of a FIFO Buffer the NEWDAT bit of this
Message Object is set. By setting NEWDAT while EOB is zero the Message Object is
locked for further write accesses by the Message Handler until the CPU has written the
NEWDAT bit back to zero.
Messages are stored into a FIFO Buffer until the last Message Object of this FIFO Buffer
is reached. If none of the preceding Message Objects is released by writing NEWDAT to
zero, all further messages for this FIFO Buffer will be written into the last Message Object
of the FIFO Buffer and therefore overwrite previous messages.
When the CPU transfers the contents of Message Object to the IFx Message Buffer
registers by writing its number to the IFx Command Request Register, bits NEWDAT and
INTPND in the corresponding Command Mask Register should be reset to zero
(TXRQST/NEWDAT = ‘1’ and ClrINTPND = ‘1’). The values of these bits in the Message
Control Register always reflect the status before resetting the bits.
To assure the correct function of a FIFO Buffer, the CPU should read out the Message
Objects starting at the FIFO Object with the lowest message number.
16.7.3.8.
All information provided in this document is subject to legal disclaimers.
Rev. 12 — 24 September 2012
Chapter 16: LPC111x/LPC11Cxx C_CAN controller
UM10398
© NXP B.V. 2012. All rights reserved.
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