pcf2127a NXP Semiconductors, pcf2127a Datasheet - Page 16

• Manufacturer Part Number: pcf2127a
• Description: Integrated Rtc, Tcxo And Quartz Crystal
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCF2127A_1
Product data sheet
8.5.5.2 Reading from the RAM
8.6 Power management functions
For details see
For details see
The PCF2127A has two power supply pins and one power output pin:
The PCF2127A has three power management functions implemented:
The power management functions are controlled by the control bits PWRMNG[2:0] in
register Control_3:
Table 17.
PWRMNG[2:0]
000
001
010
3. Write data into the RAM:
1. Set RAM address:
2. Send RAM read command:
3. Read from the RAM:
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•
•
•
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– Write n data byte into RAM.
– Select register RAM_addr_MSB (send address 1Ah).
– Set value for bit RA8 (data byte of register 1Ah);
– Set value for array RA[7:0] (data byte of register 1Bh).
– Select register RAM_rd_cmd (send address 1Dh).
– Read n data byte from the RAM.
V
V
BBS - battery backed output voltage pin (equal to the internal power supply)
Battery switch-over function
Battery low detection function
Extra power fail detection function
DD
BAT
note: register address will be incremented automatically to 1Bh.
- the main power supply input pin
- the battery backup input pin
Power management control bit description
Figure
Figure
[1]
Function
battery switch-over function is enabled in standard mode;
battery low detection function is enabled;
extra power fail detection function is enabled
battery switch-over function is enabled in standard mode;
battery low detection function is disabled;
extra power fail detection function is enabled
battery switch-over function is enabled in standard mode;
battery low detection function is disabled;
extra power fail detection function is disabled
Rev. 01 — 21 January 2010
44.
45.
Integrated RTC, TCXO and quartz crystal
PCF2127A
© NXP B.V. 2010. All rights reserved.
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