EM260-USART-JMP-R Ember, EM260-USART-JMP-R Datasheet - Page 23
![KIT JUMP START FOR EM260](/photos/14/10/141066/mfg_em260-usart-jmp-r_sml.jpg)
EM260-USART-JMP-R
Manufacturer Part Number
EM260-USART-JMP-R
Description
KIT JUMP START FOR EM260
Manufacturer
Ember
Series
JumpStartr
Type
802.15.4/Zigbeer
Specifications of EM260-USART-JMP-R
Frequency
2.4GHz
For Use With/related Products
EM260
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Other names
636-1004
EM260-JMP
EM260-JMP
5 SPI Protocol (Version Number 1)
5.1
5.2
Physical Interface Configuration
SPI Transaction
The EM260 Low Level Protocol centers on the SPI interface for communication with a pair of GPIO for hand-
shake signaling. The following are the primary design goals for the Low Level Protocol:
The EM260 supports both SPI Slave Mode 0 (clock is idle low, sample on rising edge) and SPI Slave Mode 3
(clock is idle high, sample on rising edge) at a maximum SPI clock rate of 5MHz, as illustrated in Figure 3. The
convention for the waveforms in this document is to show Mode 0.
The nHOST_INT signal and the nWAKE signal are both active low. The Host must supply a pull-up resistor on
the nHOST_INT signal to prevent errant interruptions during undefined events such as the EM260 resetting.
The EM260 supplies an internal pull-up on the nWAKE signal to prevent errant interruptions during undefined
events such as the Host resetting.
The basic EM260 SPI transaction is half-duplex to ensure proper framing and to give the EM260 adequate
response time. The basic transaction, as shown in Figure 4, is composed of three sections: Command, Wait,
and Response. The transaction can be considered analogous to a function call. The Command section is the
function call, and the Response section is the return value.
5.2.1
The Host begins the transaction by asserting the Slave Select and then sending a command to the EM260. This
command can be of any length from 2 to 128 bytes and must not begin with 0xFF. During the Command
section, the EM260 will respond with only 0xFF. The Host should ignore data on MISO during the Command
section. Once the Host has completed transmission of the entire message, the transaction moves to the Wait
section.
EM260 – Slave (MISO)
Host – Master (MOSI)
The EM260 looks like a hardware peripheral.
The EM260 is the slave device and all transactions are initiated by the Host (the master).
The EM260 supports a reasonably high data rate.
Command Section
Clock (SCLK)
Figure 4. General Timing Diagram for a SPI Transaction
Figure 3. SPI Transfer Format, Mode 0 and Mode 3
MSB
MSB
LSB
LSB
120-1003-000D
EM260
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