L9663-1 PSI5收发器不通过SPI通信

我们希望使用L9663 PSI5收发器连接传感器。 STM32 Discovery板用作SPI主站，模式1（CPOL = 0，CPHA = 1）。 SPI时钟速度设置为10MHz。

模块配置是：

/ * SPI1参数配置* /
hspi1.Instance = SPI1;
hspi1.Init.Mode = SPI_MODE_MASTER;
hspi1.Init.Direction = SPI_DIRECTION_2LINES;
hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
hspi1.Init.CLKPhase = SPI_PHASE_2EDGE;
hspi1.Init.NSS = SPI_NSS_SOFT;
hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2;
hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi1.Init.CRCPolynomial = 11;

我们将32位帧发送到数据表中指定格式的设备（帧定义部分，第84-85页）。

但是，IC没有响应任何SPI命令，并且MISO线始终保持高电平。我们通过成功连接MCP2515 SPI CAN控制器，验证了STM32板的SPI模块是否正常工作。即在MISO线上获得SPI响应和活动。

我们还验证了每个SPI事务的时钟周期数是正确的（数据表中指定的32个时钟周期，第87页）。

收发器提供了文档（第15页）中描述的配置之一，具有以下值（均在操作范围内）：

VB = 12V - 在引脚和GND之间包含一个75nF电容
VDD = 5V - 在引脚和GND之间包含一个75nF电容
VASSUP = 0V（电荷泵关闭）
VAS = 7.6V（使用外部稳压）
在VINTD和DGND引脚上包含一个75nF电容。

由于我们使用裸露焊盘TQFP32封装，焊盘焊接到GND平面。根据数据表（第11页）的规定，所有接地都保持电气短路。 TM引脚也连接到GND。

我们还通过测量VINTD引脚上的输出电压确认设备已打开，该设备启用时为3.3V，上电时消耗约19mA。

有人可以说明为什么设备没有在MISO线上回传？



以下为原文

We want to use the L9663 PSI5 Transceiver to interface a sensor. A STM32 Discovery board is being used as the SPI master, in mode 1 (CPOL = 0, CPHA = 1). The SPI clock speed is set to 10MHz.

The module configuration is:

/* SPI1 parameter configuration*/
hspi1.Instance = SPI1;
hspi1.Init.Mode = SPI_MODE_MASTER;
hspi1.Init.Direction = SPI_DIRECTION_2LINES;
hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
hspi1.Init.CLKPhase = SPI_PHASE_2EDGE;
hspi1.Init.NSS = SPI_NSS_SOFT;
hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_2;
hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi1.Init.CRCPolynomial = 11;

We are sending 32 bit frames to the device formatted as specified on the datasheet (Frame definition section, pages 84-85) .

However, the IC is not responding to any SPI commands, and the MISO line stays always high. We have verified that the SPI module of the STM32 board functions properly, by interfacing a MCP2515 SPI CAN controller successfully. i.e. getting an SPI response and activity on the MISO line.

We have also verified that the number of clock cycles for each SPI transaction is correct (32 clock cycles as specified on the datasheet, page 87).

The transceiver has been supplied with one of the configurations described in the documentation (page 15), with the following values (all within the operational range):

VB = 12V - Including a 75nF capacitor between the pin and GND
VDD = 5V - Including a 75nF capacitor between the pin and GND
VASSUP = 0V (Charge pump off)
VAS = 7.6V (Using an external regulated voltage)
Included a 75nF capacitor across the pins VINTD and DGND.

Since we are using the exposed pad TQFP32 package, the pad is soldered to a GND plane. All the grounds have been kept electrically shorted, as specified on the datasheet (page 11). The TM pin is also connected to GND.

We have also confirmed that the device is switched on, by measuring the output voltage on the VINTD pin, which is 3.3V when the device is enabled, consuming around 19mA when powered up.


Could someone please describe why the device is not communicating back on the MISO line?