■
RST# pin
■
Power-on reset
■
USB charger attach reset
■
Software configured watchdog timer
The RST# pin is an active low reset and is internally filtered using the internal low frequency clock oscillator. CSR
recommends applying RST# for a period >5ms.
At reset the digital I/O pins are set to inputs for bidirectional pins and outputs are set to tristate.
10.10.1 Digital Pin States on Reset
Table 10.2 shows the pin states of CSR8640 BGA on reset.
Pin Name / Group
I/O Type
Full Chip Reset
USB_DP
Digital bidirectional
USB_DN
Digital bidirectional
PIO[0]
Digital bidirectional
PUS
PIO[1]
Digital bidirectional
PUS
PIO[2]
Digital bidirectional
PDW
PIO[3]
Digital bidirectional
PDW
PIO[4]
Digital bidirectional
PDW
PIO[5]
Digital bidirectional
PDW
PIO[6]
Digital bidirectional
PDS
PIO[7]
Digital bidirectional
PDS
PIO[8]
Digital bidirectional
PUS
PIO[9]
Digital bidirectional
PDS
PIO[10]
Digital bidirectional
PDS
PIO[11]
Digital bidirectional
PDS
PIO[12]
Digital bidirectional
PUS
PIO[13]
Digital bidirectional
PDS
PIO[14]
Digital bidirectional
PUS
PIO[15]
Digital bidirectional
PUS
Advance Information
This material is subject to CSR's non-disclosure agreement
© Cambridge Silicon Radio Limited 2011
Page 67 of 110
CS-209182-DSP1
CSR8640 BGA
Data Sheet