JN5139/001,515 NXP Semiconductors, JN5139/001,515 Datasheet - Page 35

• Manufacturer Part Number: JN5139/001,515
• Description: IC MCU 32BIT 56QFN
• Manufacturer: NXP Semiconductors

Specifications of JN5139/001,515

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

because neither party has data to send or because the receiver does not have a buffer available. If the data length is
non-zero, the data in the JN5139 transmit memory buffer is sent, beginning at the start of the buffer. At the same
time that data bytes are being sent from the transmit buffer, the JN5139 receive buffer is being filled with incoming
data, beginning from the start of the buffer.
The remote processor, acting as the master, must determine the larger of its incoming or outgoing data transfers and
deassert IP_SEL when all of the transmit and receive data has been transferred. The data is transferred into or out of
the buffers starting from the lowest address in the buffer, and each word is assembled with the MSB first on the serial
data lines. Following a transaction, IP_SEL must be high (deasserted) for at least 300nsec before a further
transaction can begin.
IP_SEL
IP_CLK
IP_DI
padding (8 bit)
data length or 0s (8 bit)
N words of data
Status (8 bit)
N words of data
IP_DO
data length or 0s (8 bit)
padding (8 bit)
Status (8 bit)
Figure 25: Intelligent Peripheral Data Transfer Waveform
11.2 JN5139 (Slave) Initiated Data Transfer
To send data, the data is written into either buffer 0 or 1 of the intelligent peripheral memory area. Then the buffer
number is written together with the data length. If the call is successful, the interrupt line IP_INT will signal to the
remote processor that there is a message ready to be sent from the JN5139. When a remote processor starts a
transfer to the JN5139 by deasserting IP_SEL, then IP_INT is deasserted. If the transfer is unsuccessful and the
data is not output then IP_INT is reasserted after the transfer to indicate that data is still waiting to be sent.
The interface can be configured to generate an internal interrupt whenever a transaction completes (for example
IP_SEL becomes inactive after a transfer starts). It is also possible to mask the interrupt. The end of the
transmission can be signalled by an interrupt, or the interface can be polled.
To receive data the interface must be firstly initialised and when this is done, the bit RXRDY sent in the status byte
from the IP block will show that data can be received by the JN5139. Successful data arrival can be indicated by an
interrupt, or the interface can be polled. IP_INT is asserted if the JN5139 is configured to be able to receive, and the
remote processor has previously attempted to send data but the RXRDY indicated that it could not be sent.
To send and receive at the same time, the transmit and receive buffers must be set to be different.
11.3 Remote Processor (Master) Initiated Data Transfer
The remote processor (master) must initiate a transfer to send data to the JN5139 (slave) by asserting the slave
select pin, IP_SEL, and generating its status byte on IP_DI with TXRDY set. After receiving the status byte from the
JN5139, the master should check that the JN5139 has a buffer ready by reading the RXRDY bit of the received
status byte. If the RXRDY bit is 0 indicating that the JN5139 cannot accept data, it must terminate the transfer by
deasserting IP_SEL unless it is receiving data from the JN5139. If the RXRDY bit is 1, indicating that the JN5139 can
accept data, then the master should generate a further 8 clocks on IP_CLK in order to transfer its own message
length on IP_DI. The master must continue clocking the interface until sufficient clocks have been generated to send
all the data specified in the length field to the JN5139. The master must then deassert IP_SEL to show the transfer
is complete.
The master may initiate a transfer to read data from the JN5139 by asserting the slave select pin, IP_SEL, and
generating its status byte on IP_DI with RXRDY set. After receiving the status byte from the JN5139, it should check
that the JN5139 has a buffer ready by reading the TXRDY bit of the received status byte. If the TXRDY bit is 0,
indicating that the JN5139 does not have data to send, it must terminate the transfer by deasserting IP_SEL unless it
is transmitting data to the JN5139. If the TXRDY bit is 1, indicating that the JN5139 can send data, then the master
must generate a further 8 clocks on IP_CLK in order to receive the message length on IP_DO. The master must
continue clocking the interface until sufficient clocks have been generated to receive all the data specified in the
length field from the JN5139. The master should then deassert IP_SEL to show the transfer is complete.
Data can be sent in both directions at once and the master must ensure both transfers have completed before
deasserting IP_SEL.
Note: The remote processor must not attempt to transfer before a previous receive has been processed.
© NXP Laboratories UK 2010
JN-DS-JN5139 1v9
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