FM3204 Ver la hoja de datos (PDF) - Unspecified
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componentes Descripción
Fabricante
FM3204 Datasheet PDF : 20 Pages
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be tied to 5V since the VBAK (max) specification
will be exceeded. A 1 µF capacitor will keep
the companion functions working for about 1.5
second.
Although VBAK may be connected to VSS, this is not
recommended if the companion is used. None of the
companion functions will operate below about 2.5V.
FM3204/16/64/256
! Note: systems using lithium batteries should clear
the VBC bit to 0 to prevent battery charging. The
VBAK circuitry includes an internal 1 KΩ series
resistor as a safety element.
Register Map
The processor companion functions are accessed via 16 special function registers that are mapped to a separate 2-
wire device ID. The interface protocol is described below. The registers contain control bits, or information flags. A
description of each register follows.
Register Map Summary Table
Nonvolatile =
Battery-backed =
Address
18h
17h
16h
15h
14h
13h
12h
11h
10h
0Fh
0Eh
0Dh
0Ch
0Bh
0Ah
09h
00-08h
D7
-
SNL
WDE
WTR
D6
-
-
-
POR
Data
D5
D4
D3
Serial Number Byte 7
Serial Number Byte 6
Serial Number Byte 5
Serial Number Byte 4
Serial Number Byte 3
Serial Number Byte 2
Serial Number Byte 1
Serial Number Byte 0
Counter 2 MSB
Counter 2 LSB
Counter 1 MSB
Counter 1 LSB
-
-
RC
-
WP1
WP0
-
WDT4 WDT3
LB
-
W R3
DO NOT USE
D2
CC
VBC
WDT2
WR2
D1
C2P
VTP1
WDT1
WR1
D0
C1P
VTP0
WDT0
WR0
Function
Range
Serial Number 7
FFh
Serial Number 6
FFh
Serial Number 5
FFh
Serial Number 4
FFh
Serial Number 3
FFh
Serial Number 2
FFh
Serial Number 1
FFh
Serial Number 0
FFh
Event Counter 2 MSB FFh
Event Counter 2 LSB FFh
Event Counter 1 MSB FFh
Event Counter 1 LSB FFh
Event Count Control
Companion Control
Watchdog Control
Watchdog Restart/Flags
RESERVED
*Note that the usable address range starts at address 09h to preserve software compatibility with the FM31xx
device family, which includes a real-time clock in registers 00-08h.
Note: When the device is first powered up and programmed, all registers must be written because the battery-
backed register values cannot be guaranteed. The table below shows the default values of the non-volatile
registers. All other register values should be treated as unknown.
Default Register Values
Address Hex Value
18h 0x00
17h 0x00
16h 0x00
15h 0x00
14h 0x00
13h 0x00
12h 0x00
11h 0x00
0Bh 0x00
0Ah 0x1F
Rev 2.1
Dec. 2004
Page 7 of 20
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