參數(shù)資料
型號(hào): SAA7146AH
廠商: NXP SEMICONDUCTORS
元件分類: 消費(fèi)家電
英文描述: .012UF/400VDC METAL POLY CAP
中文描述: SPECIALTY CONSUMER CIRCUIT, PQFP160
封裝: 28 X 28 MM, 3.40 MM HEIGHT, PLASTIC, SOT322-2, MS-022, QFP-160
文件頁(yè)數(shù): 30/144頁(yè)
文件大?。?/td> 645K
代理商: SAA7146AH
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)第28頁(yè)第29頁(yè)當(dāng)前第30頁(yè)第31頁(yè)第32頁(yè)第33頁(yè)第34頁(yè)第35頁(yè)第36頁(yè)第37頁(yè)第38頁(yè)第39頁(yè)第40頁(yè)第41頁(yè)第42頁(yè)第43頁(yè)第44頁(yè)第45頁(yè)第46頁(yè)第47頁(yè)第48頁(yè)第49頁(yè)第50頁(yè)第51頁(yè)第52頁(yè)第53頁(yè)第54頁(yè)第55頁(yè)第56頁(yè)第57頁(yè)第58頁(yè)第59頁(yè)第60頁(yè)第61頁(yè)第62頁(yè)第63頁(yè)第64頁(yè)第65頁(yè)第66頁(yè)第67頁(yè)第68頁(yè)第69頁(yè)第70頁(yè)第71頁(yè)第72頁(yè)第73頁(yè)第74頁(yè)第75頁(yè)第76頁(yè)第77頁(yè)第78頁(yè)第79頁(yè)第80頁(yè)第81頁(yè)第82頁(yè)第83頁(yè)第84頁(yè)第85頁(yè)第86頁(yè)第87頁(yè)第88頁(yè)第89頁(yè)第90頁(yè)第91頁(yè)第92頁(yè)第93頁(yè)第94頁(yè)第95頁(yè)第96頁(yè)第97頁(yè)第98頁(yè)第99頁(yè)第100頁(yè)第101頁(yè)第102頁(yè)第103頁(yè)第104頁(yè)第105頁(yè)第106頁(yè)第107頁(yè)第108頁(yè)第109頁(yè)第110頁(yè)第111頁(yè)第112頁(yè)第113頁(yè)第114頁(yè)第115頁(yè)第116頁(yè)第117頁(yè)第118頁(yè)第119頁(yè)第120頁(yè)第121頁(yè)第122頁(yè)第123頁(yè)第124頁(yè)第125頁(yè)第126頁(yè)第127頁(yè)第128頁(yè)第129頁(yè)第130頁(yè)第131頁(yè)第132頁(yè)第133頁(yè)第134頁(yè)第135頁(yè)第136頁(yè)第137頁(yè)第138頁(yè)第139頁(yè)第140頁(yè)第141頁(yè)第142頁(yè)第143頁(yè)第144頁(yè)
1998 Apr 09
30
Philips Semiconductors
Product specification
Multimedia bridge, high performance
Scaler and PCI circuit (SPCI)
SAA7146A
7.2.5
I
NTERNAL ARBITRATION CONTROL
The SAA7146A has up to three video DMA channels, four
audio DMA channels and three other DMA channels (RPS,
MMU and DEBI) each trying to get access to the PCI-bus.
To handle this, an Internal Arbitration Control (INTAC) is
needed. INTAC controls on the one hand the PCI-bus
requests and on the other hand the order in which each
DMA channel gets access to the bus.
The basic implementation of the internal arbitration control
is a round-robin mechanism on the top, consisting of the
RPS, the MMU and one of the eight data channels. Data
channel arbitration is performed using a ‘first come first
serve’ queue architecture, which may consist of up to eight
entries.
Each data channel reaching a certain filling level of its
FIFO defined by the threshold, is allowed to make an entry
into the arbitration queue. The threshold defines the
number of Dwords needed to start a sensible PCI transfer
and must be small enough to avoid a loss of data due to an
overflow regarding the PCI latency time. After each job
(Video Transfer Done, VTD) the video channels have to be
emptied and are allowed to fill an entry into the queue,
even if they have not yet reached their threshold.
Concurrently to the entry the channel sets a bit which
prohibits further entries to this channel. In the worst case,
each data channel can have only one entry in the queue.
If each channel wants to access the bus, which means the
queue is full, an order like the one shown below will be
given.
MMU
RPS.
First entry of the data channel queue:
MMU
RPS.
Second entry of the data channel queue:
MMU
and so on.
If INTAC detects at least one DMA channel in the queue or
an MMU or an RPS request, it signals the need for the bus
by setting the REQ# signal on the PCI-bus. If the GNT#
signal goes LOW, the SAA7146A is the owner of the bus
and makes the PCI master module working with the first
channel selected. The master module tries to transfer the
number of Dwords defined in the Burst Register. For RPS
the burst length is hardwired to four and for the MMU it is
hardwired to two Dwords. After that the master module
stops this transfer and starts a transfer using the next
channel (due to the round-robin).
If a DMA channel gets its transfer stopped due to a retry,
the arbitration control sets the corresponding retry flag.
INTAC tries to end a retried transfer, even if this transfer
gets stopped via the Transfer Enable bit (TR_E). For this
reason the Transfer Enable bits are internally shadowed
by INTAC. A transfer can only be stopped if it has no retry
pending.
The Arbitration Control Registers (Burst and Threshold of
DEBI, Video 1 to 3, Audio 1 to 4) are listed in Table 6.
相關(guān)PDF資料
PDF描述
SAA7146A Multimedia bridge, high performance Scaler and PCI circuit SPCI
SAA7151 Digital multistandard colour decoder with SCART interface DMSD2-SCART
SAA7151B Digital multistandard colour decoder with SCART interface DMSD2-SCART
SAA7157 Clock signal generator circuit for digital TV systems SCGC
SAA7157T Clock signal generator circuit for digital TV systems SCGC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SAA7146AH/V3,557 制造商:NXP Semiconductors 功能描述:
SAA7146AH/V4,557 功能描述:視頻 IC VIDEO PCI BRIDGE (QFP160) RoHS:否 制造商:Fairchild Semiconductor 工作電源電壓:5 V 電源電流:80 mA 最大工作溫度:+ 85 C 封裝 / 箱體:TSSOP-28 封裝:Reel
SAA7146AH-V4.557 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Multimedia bridge, high performance Scaler and PCI circuit
SAA7146AHZ 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Multimedia bridge, high performance Scaler and PCI circuit SPCI
SAA7151 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Digital multistandard colour decoder with SCART interface DMSD2-SCART