Hardware Reference - Stollmann
Hardware Reference - Stollmann
Hardware Reference - Stollmann
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
BlueMod+B20/AI<br />
BlueMod+B20/AP<br />
BlueMod+B20/AP/L<br />
3.2 Reset<br />
BlueMod+B20/AI, BlueMod+B20/AP/L and BlueMod+B20/AP are equipped with<br />
circuitry for generating Power ON Reset from the internal core voltage. A reset is<br />
generated when the core voltage falls below typically 1.5V and is released when it<br />
rises above typically 1.6V.<br />
Via Pin 31 an external reset is generated by holding RESET# at ≤ 0.3V for ≥ 5ms.<br />
It is strongly recommended to use external Power ON Reset circuitry, which holds<br />
RESET# at ≤ 0.3V for ≥ 5ms after VSUP has stabilized in the recommended voltage<br />
range.<br />
The following table shows the pin states of BlueMod+B20 on reset.<br />
Pin Name<br />
PIO[11:0]<br />
PCM_OUT<br />
PCM_IN<br />
PCM_SYNC<br />
PCM_CLK<br />
UART_TX<br />
UART_RX<br />
UART_RTS#<br />
UART_CTS#<br />
USB_DP<br />
USB_DN<br />
SPI_CS#<br />
SPI_CLK<br />
SPI_MOSI<br />
SPI_MISO<br />
AIO[2:0]<br />
RESET#<br />
State: BlueMod+B20<br />
Input with weak pull down<br />
Output tri-stated with weak pull down<br />
Input with weak pull down<br />
Input with weak pull down<br />
Input with weak pull down<br />
Output tri-stated with weak pull up<br />
Input with weak pull down<br />
Output tri-stated with weak pull up<br />
Input with weak pull down<br />
Input with weak pull down<br />
Input with weak pull down<br />
Input with weak pull up<br />
Input with weak pull down<br />
Input with weak pull down<br />
Output tri-stated with weak pull down<br />
Output, driving low<br />
Input with weak pull up<br />
3.2.1 UART configuration in reset<br />
The UART interface for BlueMod+B20 while the chip is being held in reset is tristate.<br />
This will allow the user to daisy chain devices onto the physical UART bus. The<br />
constraint on this method is that any devices connected to this bus must tristate<br />
when BlueMod+B20 reset is de-asserted and the firmware begins to run.<br />
Release r09 www.stollmann.de Page 12 of 55
Change language