数据搜索系统,热门电子元器件搜索 |
|
ISL5217 数据表(PDF) 7 Page - Intersil Corporation |
|
ISL5217 数据表(HTML) 7 Page - Intersil Corporation |
7 / 43 page 7 FN6004.3 July 8, 2005 microprocessors can share a single QPUC as shown in Figure 3. Parallel The parallel mode allows the µP to write the I and Q samples directly to the FIFO holding registers. The parallel input format is selected when Serial control (0x11, bit 15) is low. The normal µP write order is the Q sample, Control word 0x1, followed by the I sample, Control word 0x0. Writing to Control word 0x0 generates the update strobe to move the data from the FIFO holding register into the first location of the I/Q FIFO. The first location of the I/Q FIFO is available for read back. The µP can perform back-to-back write accesses to Control words 0x1 and 0x0, but must maintain four fCLK periods between accesses to the same address. This limits the maximum µP write access rate for an I/ Q sample pair to 104MHz/4 = 26MHz. The Read/Write format for a parallel data transfer is shown in Figure 4 FIFO The FIFO provides the interface and data storage between the input source and the shaping filter or FM modulator. The FIFO can hold up to seven I /Q sample pairs. The block diagram is shown in Figure 6. The input source to the FIFO is selected by Serial control (15). The FIFO pointer is incremented every time data is written into the FIFO. The transferring of data into the FIFO does not occur until both I and Q have been received when the sample data is input in a serial fashion. When the sample data is input in a parallel fashion, the transferring of data into the FIFO occurs when the µP writes to Control Word 0 (I data). While the input source determines the write rate, the shaping filter determines the read rate. The maximum read rate occurs when the shaping filter constraints for Data Span (DS) and Interpolation Phases (IP) equal four. For a clock rate of 104MHz, the maximum read rate is determined by fCLK/(DS)(IP), which is 104MHz/16 = 6.5MHz. See the Shaping Filter Section for more details. When the Shaping Filter requires another data sample, a request is made to the FIFO for data and the FIFO pointer is decremented. Figure 5 indicates the timing of a request for data from the Shaping filter to the actual appearance of data at the FIFO output. An “empty” FIFO detection causes zero valued data to be entered into the shaping filter. The FIFO can be forced to enter zero valued data by setting the on-line mode to false. The on-line mode is enabled by Main control (0xc, bit 6). A “full” FIFO detection prevents data from being pushed out of the FIFO before the filter requests it. Writing to a full FIFO is treated as an error condition that will result in a soft reset of the channel to prevent transmission of erroneous data over the air. The full FIFO channel reset can be disabled by control word 0x0c, bit 1. A programmable FIFO depth threshold sets when the FIFORDY signal is asserted, alerting the data source that more data is required. The FIFORDY signal assists the data source in maintaining the desired FIFO data depth. The data FIFO depth threshold for both I and Q inputs is set by Main control (0xc, bits 10:8). The SAMPLE CLK may be used instead of FIFORDY to indicate when data has been transferred from the FIFO to the shaping filter. See the pin description table for additional details and Figure 5 for the input data latency. FIGURE 3. MULTIPLE CONFIGURATIONS µP SCLKX FSRX SDX MASTER QPUC ISL5217 SYNCO SLAVE QPUC ISL5217 UPDX SLAVE QPUC ISL5217 SLAVE QPUC ISL5217 UPDX UPDX µP SCLKX FSRX SDX CHANNEL 0 QPUC ISL5217 µP SCLKX FSRX SDX µP SCLKX FSRX SDX µP SCLKX FSRX SDX CHANNEL 1 CHANNEL 2 CHANNEL 3 UPDX RDMODE RD WR A<6:0> CLK 01 FIGURE 4. PARALLEL DATA TRANSFER P<15:0> 00 01 00 Q I Q I 01 00 Q I ISL5217 |
类似零件编号 - ISL5217_05 |
|
类似说明 - ISL5217_05 |
|
|
链接网址 |
隐私政策 |
ALLDATASHEETCN.COM |
ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 链接交换 | 制造商名单 All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |