參數(shù)資料
型號: AD7242
廠商: Analog Devices, Inc.
英文描述: LC2MOS Dual, Complete, 12-Bit/14-Bit Serial DACs
中文描述: LC2MOS雙,完整,12-Bit/14-Bit串行數(shù)模轉(zhuǎn)換器
文件頁數(shù): 9/12頁
文件大?。?/td> 319K
代理商: AD7242
AD7242/AD7244
REV. A
–9–
MICROPROCESSOR INTERFACING
Microprocessor interfacing to the AD7242/AD7244 is via a
serial bus that uses standard protocol compatible with DSP
processors and microcontrollers. The communication interface
consists of a separate transmit section for each of the DACs.
Each section has a clock signal, a data signal and a frame or
strobe pulse.
Figures 7 through 11 show the AD7242/AD7244 configured
for interfacing to a number of popular DSP processors and
microcontrollers.
AD7242/AD7244 to ADSP-2101/ADSP-2102 Interface
Figure 7 shows a serial interface between the AD7242/AD7244
and the ADSP-2101/ADSP-2102 DSP processor. The ADSP-
2101/ADSP-2102 has two serial ports and, in the interface
shown, both serial ports are used, one for each DAC. Both serial
ports do not have to be used; in the case where only one serial
port is used, an extra line (DACA/
DACB
as shown in the other
serial interfaces) would have to decode the one
TFS
line to
provide
TFSA
and
TFSB
lines for the AD7242/AD7244.
Figure 7. AD7242/AD7244 to ADSP-2101/ADSP-2102
Interface
The three serial lines of the first serial port, SPORT1, of the
ADSP-2101/ADSP-2102 connect directly to the three serial
input lines of DACA of the AD7242/AD7244. The three serial
lines of SPORT2 connect directly to the three serial lines on the
DACB serial input port. Data from the ADSP-2101/ADSP-2102 is
valid on the falling edge of SCLK. A common LDAC signal is
used to drive the
LDACA
and
LDACB
inputs. This is shown to
be generated from a timer or clock recovery circuit but another
control or address line of the ADSP-2101/ADSP-2102 could be
used to drive these inputs. Alternatively, the
LDACA
and
LDACB
inputs of the AD7242/AD7244 could be hardwired
low; in this case the update of the DAC latches and analog
outputs takes place on the 16th falling edge of SCLK (after the
respective
TFS
signal goes low).
AD7242/AD7244 to DSP56000 Interface
A serial interface between the AD7242/AD7244 and the
DSP56000 is shown in Figure 8. The DSP56000 is configured
for normal mode, asynchronous operation with gated clock. It is
also set up for a 16-bit word with SCK and SC2 as outputs and
the FSL control bit set to a 0. SCK is internally generated on
the DSP56000 and applied to both the TCLKA and TCLKB
inputs of the AD7242/AD7244. Data from the DSP56000 is
valid on the falling edge of SCK. The serial data line, STD
drives the DTA and DTB serial input data lines of the
AD7242/AD7244.
The SC2 output provides the framing pulse for valid data. This
is an active high output and is gated with a DACA/
DACB
control line before being applied to the
TFSA
and
TFSB
inputs
of the AD7242/AD7244. The DACA/
DACB
line determines
which DAC serial data is to be transferred to, i.e., which
TFS
line is active when SC2 is active.
As in the previous interface, a common
LDAC
input is shown
driving the
LDACA
and
LDACB
inputs of the AD7242/AD7244.
Once again, these
LDAC
inputs could be hardwired low, in
which case V
OUTA
or V
OUTB
will be updated on the sixteenth
falling edge of SCK after the
TFSA
or
TFSB
input goes low.
Figure 8. AD7242/AD7244 to DSP56000 Interface
相關(guān)PDF資料
PDF描述
AD7242AQ LC2MOS Dual, Complete, 12-Bit/14-Bit Serial DACs
AD7242BQ LC2MOS Dual, Complete, 12-Bit/14-Bit Serial DACs
AD7242JR LC2MOS Dual, Complete, 12-Bit/14-Bit Serial DACs
AD7242KR LC2MOS Dual, Complete, 12-Bit/14-Bit Serial DACs
AD7244 LC2MOS Dual, Complete, 12-Bit/14-Bit Serial DACs
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD7242ACPZ 制造商:Analog Devices 功能描述:
AD7242AQ 制造商:AD 制造商全稱:Analog Devices 功能描述:LC2MOS Dual, Complete, 12-Bit/14-Bit Serial DACs
AD7242BQ 制造商:AD 制造商全稱:Analog Devices 功能描述:LC2MOS Dual, Complete, 12-Bit/14-Bit Serial DACs
AD7242JN 制造商:Analog Devices 功能描述:
AD7242JR 制造商:Analog Devices 功能描述: