| 数据搜索系统,热门电子元器件搜索 |
|
ADP5140WACCZ-R7 数据表(PDF) 49 Page - Analog Devices |
|
|
|||||||||||||||||||||||||||||
ADP5140WACCZ-R7 数据表(HTML) 49 Page - Analog Devices |
|
49 / 128 page ![]() Data Sheet ADP5140 Rev. 0 | Page 49 of 128 Figure 91 shows the SPI bit frame that has two phases. The first phase is the instruction phase that includes the command, address, and reserve. The second phase is the data phase that includes the data and cyclic redundancy check (CRC). CMD ADDR RSV DATA INSTRUCTION PHASE CRC DATA PHASE Figure 91. SPI Bit Frame Command (CMD) CMD is an 8-bit field that indicates the action that the host wants to perform, as shown in Table 32. Table 32. Command Byte Description Bit(s) Description 7 0: write operation 1: read operation 6 0: broadcast disable 1: broadcast enable 5 Reserved 4 0: little Endian 1: big Endian (default) 3 0: MSB first (default) 1: LSB first [2:1] Device index 0 0: write operation 1: read operation Bit 7 and Bit 0 in this field indicate whether the host wants to perform a write (00) or a read (11) operation, respectively. Note that 01 and 10 are invalid values. Bit 1 and Bit 2 in this field indicate the device index of the ADP5140 to which the host wants to communicate. The device index is determined by the MODE pin configuration in Table 27. Bit 3 and Bit 4 in this field indicate the SPI communication command mode of the ADP5140 with big Endian and MSB first as the default. The command mode is programmable through the SPI IF_CFGA register. The ADP5140 supports the following four types of command modes: • Mode 0: little Endian and MSB first. • Mode 1: little Endian and LSB first. • Mode 2: big Endian and MSB first (default). • Mode 3: big Endian and LSB first. Note that if the broadcast feature is enabled (Bit 6 in CMD is set to 1), any device with the CS pin pulled low is under communication despite the device index value (Bit 1 and Bit 2 in CMD). Address (ADDR) ADDR is a 2-byte field that contains the register address the host wants to access. The ADDR field duration is 16 SCK cycles. Refer to the SPI Register Map section for more information. Reserved (RSV) RSV is a 1-byte field reserved by the ADP5140. The RSV field duration is eight SCK cycles. Data (DATA) DATA is a 4-byte field that contains the data to transfer. The DATA field duration is 32 SCK cycles. CRC The ADP5140 uses the CRC field to detect data communication errors in each SPI frame. The CRC field in the SPI frame is a 16-bit field containing the computed CRC value. CRC is always sent MSB first and spans over the CMD, ADDR, RSV, and DATA fields. The default polynomial used to calculate CRC is x16 + x15 + x12 + x7 + x6 + x4 + x3 + 1 (0x90D9), and the default initial seed value to calculate CRC is 0x5555. Both the polynomial and initial seed values can be configured in the SPI_CRC_PARAM register. Figure 92 and Figure 93 show the time sequence of SPI write and read operations. C7:C0 R7:R0 A7:A0 A15:A8 D7:D0 D15:D8 D23:D16 D31:D24 CRC15:CRC0 MOSI CS COMMAND ADDRESS RESERVED DATA CRC HIGH IMPEDANCE MISO Figure 92. SPI Write Operation C7:C0 MOSI CS COMMAND ADDRESS RESERVED DATA CRC MISO R7:R0 A7:A0 A15:A8 D7:D0 D15:D8 D23:D16 D31:D24 CRC15:CRC0 Figure 93. SPI Read Operation |
|
链接网址 |
| 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 | 数据表链接 | 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 |