ISLA224P
CSB STALLING
CSB
SCLK
SDIO
INSTRUCTION/ADDRESS
DATA WORD 1
DATA WORD 2
FIGURE 42. 2-BYTE TRANSFER
LAST LEGAL
CSB
SCLK
CSB STALLING
SDIO
INSTRUCTION/ADDRESS
DATA WORD 1
DATA WORD N
FIGURE 43. N-BYTE TRANSFER
Serial Peripheral Interface
A serial peripheral interface (SPI) bus is used to facilitate
configuration of the device and to optimize performance. The SPI
bus consists of chip select (CSB), serial clock (SCLK) serial data
output (SDO), and serial data input/output (SDIO). The maximum
SCLK rate is equal to the A/D sample rate (f SAMPLE ) divided by 32
for write operations and f SAMPLE divided by 132 for reads. At
f SAMPLE = 250MHz, maximum SCLK is 15.63MHz for writing and
3.79MHz for read operations. There is no minimum SCLK rate.
The following sections describe various registers that are used to
configure the SPI or adjust performance or functional parameters.
Many registers in the available address space (0x00 to 0xFF) are
not defined in this document. Additionally, within a defined
register there may be certain bits or bit combinations that are
reserved. Undefined registers and undefined values within defined
registers are reserved and should not be selected. Setting any
reserved register or value may produce indeterminate results.
SPI Physical Interface
The serial clock pin (SCLK) provides synchronization for the data
transfer. By default, all data is presented on the serial data
input/output (SDIO) pin in three-wire mode. The state of the SDIO
pin is set automatically in the communication protocol
(described in the following). A dedicated serial data output pin
(SDO) can be activated by setting 0x00[7] high to allow operation
in four-wire mode.
The SPI port operates in a half duplex master/slave
configuration, with the ISLA224P25 functioning as a slave.
Multiple slave devices can interface to a single master in
three-wire mode only, since the SDO output of an unaddressed
device is asserted in four wire mode.
The chip-select bar (CSB) pin determines when a slave device is
being addressed. Multiple slave devices can be written to
concurrently, but only one slave device can be read from at a
given time (again, only in three-wire mode). If multiple slave
24
devices are selected for reading at the same time, the results will
be indeterminate.
The communication protocol begins with an instruction/address
phase. The first rising SCLK edge following a high-to-low
transition on CSB determines the beginning of the two-byte
instruction/address command; SCLK must be static low before
the CSB transition. Data can be presented in MSB-first order or
LSB-first order. The default is MSB-first, but this can be changed
by setting 0x00[6] high. Figures 38 and 39 show the appropriate
bit ordering for the MSB-first and LSB-first modes, respectively. In
MSB-first mode, the address is incremented for multi-byte
transfers, while in LSB-first mode it’s decremented.
In the default mode, the MSB is R/W, which determines if the
data is to be read (active high) or written. The next two bits, W1
and W0, determine the number of data bytes to be read or
written (see Table 4). The lower 13 bits contain the first address
for the data transfer. This relationship is illustrated in Figure 40,
and timing values are given in “Switching Specifications” on
After the instruction/address bytes have been read, the
appropriate number of data bytes are written to or read from the
A/D (based on the R/W bit status). The data transfer will
continue as long as CSB remains low and SCLK is active. Stalling
of the CSB pin is allowed at any byte boundary
(instruction/address or data) if the number of bytes being
transferred is three or less. For transfers of four bytes or more,
CSB is allowed to stall in the middle of the instruction/address
bytes or before the first data byte. If CSB transitions to a high
state after that point the state machine will reset and terminate
the data transfer.
FN7570.1
November 30, 2012
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相关代理商/技术参数
ISLA224P 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Dual 14-Bit, 250MSPS/200MSPS/130MSPS ADC
ISLA224P12 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:High Performance Dual 14-Bit, 125MSPS ADC
ISLA224P12IRZ 制造商:Intersil Corporation 功能描述:DUAL 14-BIT 125MSPS UNBUFFERED INPUT, 72-PIN - Trays 制造商:Intersil Corporation 功能描述:IC ADC 14BIT SPI/SRL 125M 48QFN 制造商:Intersil 功能描述:Dual 14-Bit 125MSPS Unbuffered Input, 72
ISLA224P13 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Dual 14-Bit, 250MSPS/200MSPS/130MSPS ADC
ISLA224P13IRZ 制造商:Intersil Corporation 功能描述:DUAL 14-BIT 130MSPS UNBUFFERED INPUT, 72-PIN - Trays 制造商:Intersil Corporation 功能描述:IC ADC 14BIT SRL/SPI 72QFN 制造商:Intersil 功能描述:DL 14-BIT 130MSPS UNBUFRED INPUT 72PIN
ISLA224P20 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Dual 14-Bit, 250MSPS/200MSPS/130MSPS ADC
ISLA224P20IRZ 制造商:Intersil Corporation 功能描述:DUAL 14-BIT 200MSPS UNBUFFERED INPUT, 72-PIN - Trays 制造商:Intersil Corporation 功能描述:IC ADC 14BIT SRL/SPI 72QFN 制造商:Intersil 功能描述:DL 14-BIT 200MSPS UNBUFRED INPUT 72PIN 制造商:Intersil Corporation 功能描述:IC, ADC, 14BIT; Resolution (Bits):14bit; Sampling Rate:200MSPS; Supply Voltage Type:Single; Supply Voltage Min:1.7V; Supply Voltage Max:1.9V; Supply Current:375mA; Digital IC Case Style:QFN; No. of Pins:72; Data Interface:SPI ;RoHS Compliant: Yes
ISLA224P25 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Dual 14-Bit, 250MSPS/200MSPS/130MSPS ADC