参数资料
型号: AD73311LAR
厂商: ANALOG DEVICES INC
元件分类: 通信及网络
英文描述: Low Cost, Low Power CMOS General Purpose Analog Front End
中文描述: SPECIALTY TELECOM CIRCUIT, PDSO20
封装: 0.300 INCH, SOIC-20
文件页数: 34/36页
文件大小: 382K
代理商: AD73311LAR
REV. A
AD73311L
–34–
APPENDIX D
Con
fi
guring a cascade of two AD73311Ls to Operate in Mixed
Mode
This section describes a typical sequence of control words that
would be sent to a cascade of two AD73311Ls to con
fi
gure
them for operation in mixed mode. It is not intended to be a
de
fi
nitive initialization sequence, but will show users the typical
input/output events that occur in the programming and opera-
tion phases.
1
This description panel refers to Table XXII.
Steps 1
5 detail the transfer of the control words to Control
Register A, which programs the devices for Mixed-Mode opera-
tion. In Step 1, we have the
fi
rst output sample event following
device reset. The SDOFS signal is simultaneously raised on both
devices, which prepares the DSP Rx register to accept the ADC
word from Device 2 while SDOFS from Device 1 becomes an
SDIFS to Device 2. The cascade is con
fi
gured as nonFSLB,
which means that the DSP has control over what is transmitted
to the cascade
2
and in this case we will not transmit to the
devices until both output words have been received from the
AD73311Ls.
In Step 2, we observe the status of the devices following the
reception of the Device 2 output word. The DSP has received
the ADC word from Device 2, while Device 2 has received the
output word from Device 1. At this stage, the SDOFS of Device
2 is again raised because Device 2 has received Channel 1
s
output word and, as it is not addressed to Device 2, it is passed
on to the DSP.
In Step 3 the DSP has now received both ADC words. Typi-
cally, an interrupt will be generated following reception of the
two output words by the DSP (this involves programming the
DSP to use autobuffered transfers of two words). The transmit
register of the DSP is loaded with the control word destined for
Device 2. This generates a transmit frame-sync (TFS) that is
input to the SDIFS input of the AD73311L (Device 1) to indi-
cate the start of transmission.
In Step 4, Device 1 now contains the Control Word destined for
Device 2. The address
fi
eld is decremented, SDOFS1 is raised
(internally) and the Control word is passed on to Channel 2.
The Tx register of the DSP has now been updated with the
Control Word destined for Device 1 (this can be done using
autobuffering of transmit or by handling transmit interrupts
following each word sent).
In Step 5 each device has received a control word that addresses
Control Register A and sets the device count
fi
eld equal to two
devices and programs the devices into Mixed Mode
MM and
PGM
/DATA set to one. Following Step 5, the device has been
programmed into mixed-mode although none of the analog
sections have been powered up (controlled by Control Register
C). Steps 6
10 detail update of Control Register B in mixed-
mode. In Steps 6
8 the ADC samples, which are invalid as the
ADC section is not yet powered up, are transferred to the DSP
s
Rx section. In the subsequent interrupt service routine the Tx
Register is loaded with the control word for Device 2. In Steps
9
10, Devices 1 and 2 are loaded with a control word setting for
Control Register B which programs DMCLK = MCLK, the
sampling rate to DMCLK/256, SCLK = DMCLK/2.
Steps 11
17 are similar to Steps 6
12 except that Control Reg-
ister C is programmed to power up all analog sections (ADC,
DAC, Reference = 2.4 V, REFOUT). In Steps 16
17, DAC
words are sent to the device
both DAC words are necessary
as each device will only update its DAC when the device has
counted a number of SDIFS pulses, accompanied by DAC words
(in mixed-mode, the MSB = 0), that is equal to the device count
fi
eld of Control Register A
3
. As the devices are in mixed mode,
the serial port interrogates the MSB of the 16-bit word sent to
determine whether it contains DAC data or control information.
DAC words should be sent in the sequence Channel 2 followed
by Device 1.
Steps 11
17 illustrate the implementation of Control Register
update and DAC update in a single sample period. Note that
this combination is not possible in the FSLB con
fi
guration.
2
Steps 18
25 illustrate a Control Register readback cycle. In Step
22, both devices have received a Control Word that addresses
Control Register C for readback (Bit 14 of the Control Word =
1). When the devices receive the readback request, the register
contents are loaded to the serial registers as shown in Step 23.
SDOFS is raised in both devices, which causes these readback
words to be shifted out toward the DSP. In Step 24, the DSP
has received the Device 2 readback word while Device 2 has
received the Device 1 readback word (note that the address
fi
eld
in both words has been decremented to 111b). In Step 25, the
DSP has received the Device 1 readback word (its address
fi
eld
has been further decremented to 110b).
Steps 26
30 detail an ADC and DAC update cycle using the
nonFSLB con
fi
guration. In this case no Control Register update
is required.
NOTES
1
This sequence assumes that the DSP SPORT
s Rx and Tx interrupts are
enabled. It is important to ensure there is no latency (separation) between
control words in a cascade con
fi
guration. This is especially the case when
programming Control Registers A and B.
2
Mixed mode operation with the FSLB con
fi
guration is more restricted in that
the number of words sent to the cascade equals the number of devices in the
cascade, which means that DAC updates may need to be substituted with a
register write or read.
3
In mixed mode, DAC update is done using the same SDIFS counting scheme
as in normal data mode with the exception that only DAC words (MSB set to
zero) are recognized as being able to increment the frame sync counters.
相关PDF资料
PDF描述
AD73311L Low Cost, Low Power CMOS General Purpose Analog Front End Processor(低成本,低功耗的CMOS通用双模拟前端处理器)
AD73311 Low Cost, Low Power CMOS General Purpose Analog Front End Processor(低成本、低功耗、CMOS通用模拟前端处理器)
AD73322LARU Low Cost, Low Power CMOS General-Purpose Dual Analog Front End
AD73322AR Low Cost, Low Power CMOS General-Purpose Dual Analog Front End
AD73322AST Low Cost, Low Power CMOS General-Purpose Dual Analog Front End
相关代理商/技术参数
参数描述
AD73311LAR-REEL 制造商:Analog Devices 功能描述:Audio Codec 1ADC / 1DAC 16-Bit 20-Pin SOIC W T/R 制造商:Rochester Electronics LLC 功能描述:SINGLE-CHANNEL AFE I.C. - Tape and Reel
AD73311LAR-REEL7 制造商:Analog Devices 功能描述:Audio Codec 1ADC / 1DAC 16-Bit 20-Pin SOIC W T/R 制造商:Rochester Electronics LLC 功能描述:SINGLE-CHANNEL AFE I.C. - Tape and Reel
AD73311LARS 制造商:Analog Devices 功能描述:Audio Codec 1ADC / 1DAC 16-Bit 20-Pin SSOP 制造商:Rochester Electronics LLC 功能描述:SINGLE-CHANNEL AFE I.C. - Bulk 制造商:Analog Devices 功能描述:IC AUDIO CODEC
AD73311LARS-REEL 制造商:Analog Devices 功能描述:Audio Codec 1ADC / 1DAC 16-Bit 20-Pin SSOP T/R
AD73311LARSREEL7 制造商:AD 功能描述:New