BlueNRGQTR STMicroelectronics

BlueNRG, BlueNRG-MS Errata sheet 98 Errata sheet ae4c1d88- BlueNRG/BlueNRG-MS device limitations 2226-42a8-a8ca-daa3f6326f71 Silicon identification This errata sheet applies to the STMicroelectronics BlueNRG and BlueNRG-MS devices. The full list of part numbers is shown in Table 1. Table 1: Device summary (1) Order code HCI Revision Marking Package BLUENRGQTR 0x30xx BLUENRG QFN32 BLUENRGCSP 0x30xx BLUENRG WLCSP34 BLUENRG-MSQTR 0x31xx BLUENRG- QFN32 BLUENRG-MSCSP 0x31xx BLUENRG- WLCSP34 Notes: (1) As returned by HCI READ LOCAL VERSION INFORMATION. February 2017 DocID026907 Rev 4 1/5 www.st.com Limitations BlueNRG, BlueNRG-MS Errata sheet 1 Limitations 1.1 SPI CSN wakeup occurring at same time as sleep command issued 1.1.1 Part numbers affected BLUENRGQTR and BLUENRGCSP. 1.1.2 Description If SPI CSN is asserted while BlueNRG is going to sleep, the device can enter a lock state and no longer reply to SPI commands. The only way to recover the device is to perform a hardware reset. A software workaround is available to eliminate the problem. 1.1.3 Workaround The workaround involves using the IRQ signal to indicate that the external microcontroller is going to access the SPI. The details are: Use BlueNRG firmware 6.3 or later. Before asserting CS line (CS low), IRQ line must be driven high by the MCU at least 112 s. IRQ line should be set again as an input (with pull-down) after the first byte is on the SPI bus (See Figure 1:SPI access timing diagra). Figure 1: SPI access timing diagram 2/5 DocID026907 Rev 4