User Guide

NSD-5
3. System Module PAMS Technical Documentation
Page 14 Nokia Corporation Issue 1 05/02
Figure 6: External memory read cycle
Table 2: Timing information for Read/Write cycle required/provided by memory chips
MAD4/VIBRA Interface
VIBRA is a vibrating motor, used as a silent alarm device. It is driven by 11kHz or 22kHz
PWM signal, with a variable duty cycle to control the average current into the motor,
which in turn controls the intensity of the alarm. The duty cycle is set by software and
depends on the motor and the limits of the duty cycle.
Parameters Flash memory SRAM
Min (ns) Max (ns) Min (ns) Max (ns)
Memory Write
Ts(addr) 70 80
Th(addr) 0 0
Ts(data) 60 40
Th(data) 0 0
Ts(ce) 70 80
Th(ce) 0 0
Tw(we) 70 70
Memory Read
Tcyc 110 100
Td(addr) 110 100
Td(oe) 30 50
Td(ce) 110 100