參數(shù)資料
型號: T7536
廠商: Lineage Power
元件分類: Codec
英文描述: 16-Channel Programmable Codec Chip Set(十六通道可編程編解碼器芯片組)
中文描述: 16通道可編程解碼器芯片組(十六通道可編程編解碼器芯片組)
文件頁數(shù): 19/44頁
文件大?。?/td> 772K
代理商: T7536
Lucent Technologies Inc.
19
Data Sheet
February 1999
Codec Chip Set
T7531A/T7536 16-Channel Programmable
Chip Set Functional Description
(continued)
Microprocessor Start-Up of the DSP
Engine
Once the interrupt system is enabled, the DSP engine
looks for a read or write interrupt from the microproces-
sor interface once every time segment, i.e., 16 times a
frame.
If the ac coefficients for every channel are to be inde-
pendently controlled, the microprocessor can write
directly to the addresses of the 16 ac coefficient tables.
This requires a total of 16 microprocessor commands
to set up each channel, i.e., 16 frames to set up all
16 channels. Prior to activating any time slots, the
microprocessor has the option of bulk downloading the
coefficients to set up the ac coefficient tables.
When a channel needs to be set up and linked to its
time slot, the microprocessor must send the TCW for
that time slot with the modify coefficient (MC) bit (see
Table 5A). The MC bit causes the inactive routine for
that time slot to set pointers from that time-slot space to
the channel space in RAM. The MC bit also causes the
inactive routine to check the default coefficient bits of
the TCW. If set, the appropriate default table coeffi-
cients are copied over to the RAM space for the chan-
nel. This mechanism allows the microprocessor to
download a set of coefficients that can be used by mul-
tiple channels.
A mix-and-match approach can be used, i.e., some
channels are set up with independent sets of coeffi-
cients, while other channels get a default setting.
During start-up, the microprocessor must also down-
load the 16 TSA commands used by the TSA block to
map physical channels to time slots. This is required to
initialize the TSA RAM to known values. When all 16
locations have been set up, the microprocessor must
send BCW2 (0x1FFC). This flags the TSA control to
start normal operation.
Powering Up a Time Slot in the T7531A
Depending on the application, the microprocessor may
choose to set up the ac coefficients for a channel just
prior to enabling it for use. This requires 16 micropro-
cessor commands if the coefficients must be set up
from scratch, or no commands if an appropriate default
set has already been set up. In either case, the micro-
processor must ensure that all the TX and RX parts of
a channel are set up prior to enabling the time slot.
If dynamic time-slot assignment is used, the micropro-
cessor must next download a TSA command, which
the TSA block uses to map the time slot to the required
channel number.
The microprocessor must enable the time slot by set-
ting the go to powerup bit of the TCW. This causes the
DSP engine to change the TX and RX ac routine
addresses to active.
A maximum of 17 commands or a minimum of one
command is therefore needed to power up a channel.
Disabling a Time Slot in the T7531A
To disable a time slot, the microprocessor must send a
command that sets the address of either the TX or RX
ac routine to TX_inactive and RX_inactive, respectively.
The inactive routines come into use in the next TX or
RX time segment for this time slot. Upon returning from
the inactive routine, the DSP engine checks for a
microprocessor interrupt and then enters sleep mode
for the rest of the time segment.
T7536 Powerup/Powerdown
Each channel can be powered up independently. There
are two control register addresses that can be used to
control the power for each channel. In both cases, the
first bit of the address word controls the power. P = 1
for powerup, and P = 0 for powerdown.
One address is provided for each channel which con-
trols the power (0x1508—0x150F and 0x1548—
0x154F), and the address is followed by a data word
which controls the other programmable functions for
the same channel. A second address (0x1500—
0x1507 and 0x1540—0x1547) is provided for each
channel that controls only the power.
相關PDF資料
PDF描述
T7531A 16-Channel Programmable Codec Chip Set(十六通道可編程編解碼器芯片組)
T7570 Programmable PCM Codec with Hybrid-Balance Filter(帶混合平衡濾波器的可編程PCM編解碼器)
T7633 Dual T1/E1 3.3 V Short-Haul Terminator(雙T1/E1 3.3V短通信距離終端器)
T7688 5.0 V E1/CEPT Quad Line Interface(5.0 V E1/CEPT四線接口)
T7689 5.0 V T1 Quad Line Interface(5.0 V T1四線接口)
相關代理商/技術參數(shù)
參數(shù)描述
T7570 制造商:AGERE 制造商全稱:AGERE 功能描述:T7570 Programmable PCM Codec with Hybrid-Balance Filter
T-758 制造商:RHOMBUS-IND 制造商全稱:Rhombus Industries Inc. 功能描述:Transformer
T-759 制造商:RHOMBUS-IND 制造商全稱:Rhombus Industries Inc. 功能描述:SCHEMATIC DIAGRAM
T75A 制造商:EGS Appleton 功能描述:Exact Equal/ 1-5 Days
T75F-C 功能描述:非熱縮管和套管 SPIRAL WRAP 3/4 100’ RoHS:否 制造商:Panduit 產品:Cable Wraps 類型:Spiral 顏色:Black 材料:PP 內徑:0.03 in 長度:100 ft