DS1216 Datasheet, PDF (7/15 Pages) Dallas Semiconductor – SmartWatch RAM DS1216B/C/D/H SmartWatch ROM DS1216E/F

Figure 2. Reset and Memory Density Options
DS1216 SmartWatch RAM/SmartWatch ROM
NOTE: THE LETTER SUFFIX OF THE SMARTWATCH IS LOCATED ON THE PC BOARD.
The RST pin on the controller has an internal pullup resistor. To disable the RST function, the trace
between pin 1 on the socket and pin 13 on the controller can be cut. In this case, the socket will ignore the
RST input, preventing address transitions from resetting the pattern match, even if the RST bit is enabled.
On the DS1216B and DS1216D, the two V_CC pins are connected together on the PC board. The switched
V_CC from the controller is connected to the two V_CC pins that connect to the inserted RAM. No
modifications are required if the lower density RAM is used. To use the higher density RAM, the trace by
the lower density RAM V_CC pin, identified by a hash mark labeled “U,” must be cut. The two square-
metal pads, labeled “G,” must be shorted together. This disconnects switched V_CC from the pin going to
the inserted RAM, and connects it to the corresponding address input pin for the higher density RAM.
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