參數(shù)資料
型號(hào): AM8530H
廠商: Advanced Micro Devices, Inc.
英文描述: Serial Communications Controller
中文描述: 串行通信控制器
文件頁(yè)數(shù): 105/194頁(yè)
文件大?。?/td> 797K
代理商: AM8530H
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)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)當(dāng)前第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)第145頁(yè)第146頁(yè)第147頁(yè)第148頁(yè)第149頁(yè)第150頁(yè)第151頁(yè)第152頁(yè)第153頁(yè)第154頁(yè)第155頁(yè)第156頁(yè)第157頁(yè)第158頁(yè)第159頁(yè)第160頁(yè)第161頁(yè)第162頁(yè)第163頁(yè)第164頁(yè)第165頁(yè)第166頁(yè)第167頁(yè)第168頁(yè)第169頁(yè)第170頁(yè)第171頁(yè)第172頁(yè)第173頁(yè)第174頁(yè)第175頁(yè)第176頁(yè)第177頁(yè)第178頁(yè)第179頁(yè)第180頁(yè)第181頁(yè)第182頁(yè)第183頁(yè)第184頁(yè)第185頁(yè)第186頁(yè)第187頁(yè)第188頁(yè)第189頁(yè)第190頁(yè)第191頁(yè)第192頁(yè)第193頁(yè)第194頁(yè)
Support Circuitry Programming
AMD
5–11
5.5.1
The clock for the DPLL is selected by two of the commands in WR14. One command se-
lects the output of the BRG as the clock source, and the other command selects the
RTxC
pin as the clock source, independent of whether the
RTxC
pin is a simple input or
part of the crystal oscillator circuit. Note that in order to avoid metastable problems in the
counter, the clock source selection should be made only while the DPLL is disabled, since
arbitrarily narrow pulses can be generated at the output of the multiplexer when it
changes status.
DPLL Cloc k S ourc e
5.5.2
The DPLL is enabled by issuing the Enter Search Mode command in WR14. This com-
mand is also used to reset the DPLL to a known state if it is suspected that synchroniza-
tion has been lost. When used to enable the DPLL, the Enter Search Mode command
unlocks the counter, which is held while the DPLL is disabled, and enables the edge de-
tector. If the DPLL is already enabled when this command is issued, the DPLL also enters
Search mode.
DPLL Enabling
While in Search mode, the counter is held at a specific count and no outputs are pro-
vided. The DPLL remains in this status until an edge is detected in the receive data
stream. This first edge is assumed to occur on a bit cell boundary, and the DPLL will be-
gin providing an output to the receiver that will properly sample the data. As long as no
other edges are detected, the DPLL output clock will free run at a frequency equal to the
DPLL clock source divided by 32 without any phase jitter. Upon detecting another edge
the DPLL will adjust the output clock to remain in phase with the received data by adding
or subtracting a count of one. This will result in a phase jitter of
±
5.63
°
on the DPLL out-
put. Because the DPLL uses both edges of the incoming data to compare with its clock
source, a mark-space deviation of no greater than
±
1.5% (from 50%) should be main-
tained at the interface. If the first edge that the DPLL sees does not occur on a bit cell
boundary, the DPLL will eventually lock on to the receive data but it will take longer to do
so.
5.5.3
The DPLL may be programmed to operate in either NRZI or FM modes, as selected by a
command in WR14. Note that as in the case of the DPLL clock source selection, the
mode of operation should only be changed while the DPLL is disabled to prevent unpre-
dictable results.
DPLL Modes
5.5.3.1
In NRZI mode, the clock supplied to the DPLL must be 32 times the data rate. In this
mode the transmit and receive clock outputs of the DPLL are identical, and the clocks are
phased so that the receiver samples the data in the middle of the bit cell. In NRZI mode,
the DPLL does not require a transition in every bit cell, so this is useful for recovering the
clocking information from NRZ and NRZI data streams.
NRZI Mode
The DPLL uses the x32 clock along with the receive data, to construct receive and trans-
mit clock outputs that are phased to properly receive and transmit data.
To do this, the DPLL divides each bit cell into two regions, and makes an adjustment to
the count cycle of the 5-bit counter dependent upon in which region a transition on the
receive data input occurred. This is shown in Figure 5–6. Ordinarily, a bit cell boundary
will occur between count 15 and count 16, and the DPLL output will cause the data to be
sampled in the middle of the bit cell. The DPLL actually allows the transition marking a bit
cell boundary to occur anywhere during the second half of count 15 or the first half of
count 16 without making a correction to its count cycle.
相關(guān)PDF資料
PDF描述
AM85C30-10PC Enhanced Serial Communications Controller
Am85C30 Serial Communications Controller
AM85C30 Enhanced Serial Communications Controller
AM85C30-8PC Enhanced Serial Communications Controller
AM85C30-16JC Enhanced Serial Communications Controller
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AM8530H/AM85C301992 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:Am8530H/Am85C30 1992 - Am8530H/Am85C30 Serial Communications Controller
AM8530H-4DC 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Communications Controller
AM8530H-4DCB 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Communications Controller
AM8530H-4JC 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Communications Controller