EM260-RTY Ember, EM260-RTY Datasheet - Page 23

• Manufacturer Part Number: EM260-RTY
• Description: IC ZIGBEE SYSTEM-ON-CHIP 40-QFN
• Manufacturer: Ember

Specifications of EM260-RTY

• Frequency: 2.4GHz
• Data Rate - Maximum: 250kbps
• Modulation Or Protocol: 802.15.4
• Applications: ZigBee™
• Power - Output: -32dBm ~ 3dBm
• Sensitivity: -97dBm
• Voltage - Supply: 2.1 V ~ 3.6 V
• Current - Receiving: 30mA
• Current - Transmitting: 34mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Memory Size: -
• Other names: 636-1003

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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