Real Time Clock U11
©
PHYTEC Messtechnik GmbH 2011 L-710e_5
29
5
Real Time Clock U11 / SRAM U19 Backup-
Voltage
In case of a power fail or a user off event the backup-voltage AVDD_BKUP provides power to the I²C
Real Time Clock U11 (RTC8564JE) and the low power SRAM U19. In this cases a backup coincell
will supply the memory and the RTC via AVDD_BKUP (VBKUP2 of MC13783).
To set the output voltage and the different modes of VBKUP2, U14 (MC13783) must be programmed
over SPI.
Table 5:
VBKUP2 Voltage Settings
00
output = 1.0 V
01
output = 1.2 V
10
output = 1.5 V
VBKUP2[1:0]
11
output = 1.8 V
There are three bits which must be set to low/high for the different modes of VBKUP2:
VBKUP2EN:
Enables VBKUP2 in startup modes, on and user off wait modes
VBKUP2AUTOMH:
Enables VBKUP2 in memory hold modes
VBKUP2AUTOUO:
Enables VBKUP2 in user off modes
For further information refer to the MC13783 manual chapter 5.2. Operating Modes.
Summary of Contents for phyCORE-i.MX27
Page 34: ...phyCOREi MX27 26 PHYTEC Messtechnik GmbH 2011 L 710e_5 ...
Page 38: ...phyCOREi MX27 30 PHYTEC Messtechnik GmbH 2011 L 710e_5 ...
Page 52: ...phyCOREi MX27 44 PHYTEC Messtechnik GmbH 2011 L 710e_5 ...
Page 56: ...phyCOREi MX27 48 PHYTEC Messtechnik GmbH 2011 L 710e_5 ...
Page 94: ...phyCOREi MX27 86 PHYTEC Messtechnik GmbH 2011 L 710e_5 ...
Page 100: ...Published by PHYTEC Messtechnik GmbH 2011 Ordering No L 710e_5 Printed in Germany ...