8.15 Timing and Switching Characteristics
8.15.1 Power-Up Sequencing
For proper start-up of the CC3135MOD module, perform the recommended power-up sequencing as follows:
1. Tie V
BAT1
(pin 37) and V
BAT2
(pin 40) together on the board.
2. Hold the nRESET pin low while the supplies are ramping up.
shows the reset timing diagram for the first-time power-up and reset removal.
POWER
OFF
HW INIT
FW INIT
Device ready to
serve API calls
VBAT
nRESET
STATE
32-kHz
XTAL
T1
T2
T3
nHIB
RESET
Figure 8-6. First-Time Power-Up and Reset Removal Timing Diagram
describes the timing requirements for the first-time power-up and reset removal.
Table 8-7. First-Time Power-Up and Reset Removal Timing Requirements
ITEM
NAME
DESCRIPTION
MIN
TYP
MAX
UNIT
T1
nReset time
nReset timing after VBAT supplies
are stable
1
ms
T2
Hardware wake-up time
25
ms
T3
Initialization time
Internal 32-kHz XTAL settling plus
firmware initialization time plus
radio calibration
1.35
s
8.15.2 Power-Down Sequencing
For proper power down of the CC3135MOD module, ensure that the nRESET (pin 35) and nHIB (pin 4) pins
have remained in a known state for a minimum of 200 ms before removing power from the module.
8.15.3 Device Reset
When a device restart is required, the user may issue a negative pulse on either the nHIB pin (pin 4) or on
the nRESET pin (pin 35), keeping the other pulled high, depending on the configuration of the platform. If the
nRESET pin is used, the user must insure the following:
• A high-to-low reset pulse (on pin 35) of at least 200-ms duration
To ensure a proper reset sequence, the user must call the sl_stop function prior to toggling the reset.
SWRS225D – FEBRUARY 2019 – REVISED MAY 2021
Copyright © 2021 Texas Instruments Incorporated
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