DS1216B Maxim Integrated Products, DS1216B Datasheet - Page 5

• Manufacturer Part Number: DS1216B
• Description: IC SMARTWATCH RAM 16K/64K 28SOIC
• Manufacturer: Maxim Integrated Products

Specifications of DS1216B

• Controller Type: Smartwatch RAM
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 28-DIP (0.600", 15.24mm) Socket
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Figure 1. SmartWatch Comparison Register Definition
NONVOLATILE CONTROLLER OPERATION
The DS1216 SmartWatch perfor
switch is provided to direct power from the battery or V
This switch has a voltage drop of less than 0.2V. The second function that the SmartWatch provides is
power-fail detection, which occurs at V
goes out of tolerance, a comparator outputs a power-fail signal to the chip-enable logic. The third function
accomplishes write protection by holding the chip-enable signal to the memory within 0.2V of V
battery. During nominal power-supply conditions, the memory chip-enable signal will track the chip-
enable signal sent to the socket with a maximum propagation delay of 7ns for the 5V and 12ns for the
3.3V version.
FRESHNESS SEAL
Each DS1216 is shipped from Dallas Semiconductor with its lithium energy source disconnected,
ensuring full energy capacity. When V
is enabled for battery-backup operation.
BYTE 0
BYTE 1
BYTE 2
BYTE 3
BYTE 4
BYTE 5
BYTE 6
BYTE 7
NOTE: THE PATTERN RECOGNITION IN HEX IS C5, 3A, 5C, C5, 3A, A3, 5C. THE ODDS OF THIS PATTERN
ACCIDENTALLY DUPLICATING AND CAUSING INADVERTENT ENTRY TO THE SMARTWATCH ARE LESS
THAN 1 IN 10
19
. THIS PATTERN IS SENT TO THE SMARTWATCH LSB TO MSB.
0
7
1
0
1
0
1
0
1
1
1
0
0
1
1
0
0
ms circuit functions required to make a CMOS RAM nonvolatile. First, a
0
0
1
1
0
0
1
1
CC
TP
is first applied at a level greater than the lithium energy source
. The DS1216 constantly monitors the V
1
0
1
0
1
0
1
0
5 of 14
1
0
1
0
1
0
1
0
CC
1
supply, depending on which voltage is greater.
1
0
0
1
1
0
0
DS1216 SmartWatch RAM/SmartWatch ROM
0
0
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
VALUE
C5
3A
A3
5C
C5
3A
A3
5C
HEX
CC
supply. When V
CC
CC
or