User`s manual

78 rabbit.com Low-Power Design and Support
Functions are provided to power down the Realtek Ethernet chip as well. By calling the pd_powerup()
and pd_powerdown() functions, the Realtek chip can be placed in and awakened from its own power-
down mode. Note that no TCP/IP or Ethernet functions should be called while the Realtek is powered
down.
9.2.6 Baud Rates in Sleepy Mode
The available baud rates in sleepy mode are 1024, 1024/2, 1024/3, 1024/4, etc. Baud rate mismatches of
up to 5% may be tolerated. The baud rate 113.77 is available as 1024/9 and may be useful for communicat-
ing with other systems operating at 110 bps—a 3.4% mismatch. In addition, the standard PC compatible
UART 16450 with a baud rate divider of 113 generates a baud rate of 1019 bps, a 0.5% mismatch with
1024 bps. If there is a large baud rate mismatch, the serial port can usually detect that a character has been
sent to it, but can not read the exact character.
9.2.7 Debugging in Sleepy Mode
Debugging is not supported in sleepy modes. However, running with no polling (Alt-F9) will avoid the
loss of target communications when execution enters sections of code using sleepy mode, and debug com-
munications will resume when the normal operation mode is reenabled.