User's Manual

Stollmann
E + V GmbH
BlueMod+B20
Hardware reference
Author: bg Date of Saving: 28.03.07 Ref: BlueMod+B20_HWreference_V101.doc Revision: 1.00 Page 11 of 11
3.2 Reset
The BlueMod+B20 is equipped with circuitry for generating Power Down Reset from
the internal core voltage. A reset is generated when the core voltage falls below
typically 1.5V and is released when it rises above typically 1.6V.
Via Pin 31 an external reset is generated by holding RESET# at ≤ 0.3V for ≥ 5ms.
It is strongly recommended to use external Power ON Reset circuitry, which holds
RESET# at ≤ 0.3V for ≥ 5ms after VSUP has stabilized in the recommended volt-
age range.
The following table shows the pin states of BlueMod+B20 on reset.
Pin Name State: BlueMod+B20
PIO[11:0] Input with weak pull down
PCM_OUT Output tri-stated with weak pull down
PCM_IN Input with weak pull down
PCM_SYNC Input with weak pull down
PCM_CLK Input with weak pull down
UART_TX Output tri-stated with weak pull up
UART_RX Input with weak pull down
UART_RTS# Output tri-stated with weak pull up
UART_CTS# Input with weak pull down
USB_DP Input with weak pull down
USB_DN Input with weak pull down
SPI_CS# Input with weak pull up
SPI_CLK Input with weak pull down
SPI_MOSI Input with weak pull down
SPI_MISO Output tri-stated with weak pull down
AIO[2:0] Output, driving low
RESET# Input with weak pull up