ATZB-900-B0 Datasheet, PDF (15/20 Pages) ATMEL Corporation – ZigBit™ 700/800/900 MHz Wireless Modules

Specifications
5. It is strongly recommended to avoid assigning an alternate function for OSC32K_OUT pin because it is
used by BitCloud. However, this signal can be used if another peripheral or host processor requires
32.768 kHz clock, otherwise this pin can be disconnected.
6. Normally, JTAG_TMS, JTAG_TDI, JTAG_TDO, JTAG_TCK pins are used for on-chip debugging and
flash burning. They can be used for A/D conversion if JTAGEN fuse is disabled.
7. The following pins can be configured with the BitCloud software to be general-purpose I/O lines:
GPIO0, GPIO1, GPIO2, GPIO3, GPIO4, GPIO5, GPIO6, GPIO7, GPIO8, GPIO_1WR, I2C_CLK,
I2C_DATA, UART_TXD, UART_RXD, UART_RTS, UART_CTS, ADC_INPUT_3, ADC_INPUT_2,
ADC_INPUT_1, BAT, UART_DTR, USART0_RXD, USART0_TXD, USART0_EXTCLK, IRQ_7, IRQ_6.
Additionally, four JTAG lines can be programmed with software as GPIO as well, but this requires
changing the fuse bits and will disable JTAG debugging.
8. With BitCloud, CTS pin can be configured to indicate sleep/active condition of the module thus provid-
ing mechanism for power management of host processor. If this function is necessary, connection of
this pin to external pull-down resistor is recommended to prevent the undesirable transients during
module reset process.
9. Using ferrite bead and 1 µF capacitor located closely to the power supply pin is recommended, as
shown below.
10. In SPI mode, USART0_EXTCLK is output. In USART mode, this pin can be configured as either input or
output pin.
ZigBit™ 700/800/900 MHz Wireless Modules
3-8
8227C–MCU Wireless–06/09