adf7023-j Analog Devices, Inc., adf7023-j Datasheet - Page 60

• Manufacturer Part Number: adf7023-j
• Description: High Performance, Low Power, Ism Band Fsk/gfsk/msk/gmsk Transceiver Ic
• Manufacturer: Analog Devices, Inc.

ADF7023-J
WUC SETUP
Circuit Description
The ADF7023-J features a low power wake-up controller
comprising a 16-bit wake-up timer with a 3-bit programmable
prescaler, as illustrated in Figure 74. The prescaler clock source
can be configured to use either the 32.76 kHz internal RC oscillator
(RCOSC) or the 32.76 kHz external oscillator (XOSC). This
combination of programmable prescaler and 16-bit down counter
gives a total hardware timer range of 30.52 μs to 36.4 hours.
Configuration and Operation
The hardware WUC is configured via the following registers:
•
•
•
•
Table 29. WUC Register Settings
WUC Setting
WUC_VALUE_HIGH [7:0]
WUC_VALUE_LOW[7:0]
WUC_CONFIG_HIGH[7:3]
WUC_CONFIG_HIGH[2:0]
WUC_CONFIG_HIGH (Address 0x30C)
WUC_CONFIG_LOW (Address 0x30D)
WUC_VALUE_HIGH (Address 0x30E)
WUC_VALUE_LOW (Address 0x30F)
WUC
RC OSCILLATOR
32kHz XTAL
WUC_CONFIG_LOW[4]
1
0
32.768kHz
Name
WUC_TIMER_VALUE[15:8]
WUC_TIMER_VALUE[7:0]
Reserved
WUC_PRESCALER
WUC_CONFIG_HIGH[2:0]
PRESCALER
Figure 74. Hardware Wake-Up Controller (WUC)
WUC_VALUE_HIGH
Rev. 0 | Page 60 of 100
TICK RATE
Description
WUC timer value.
WUC Interval(s) = WUC_TIMER_VALUE ×
WUC timer value.
Set to 0.
WUC_PRESCALER
000
001
010
011
100
101
110
111
16-BIT DOWN
The relevant fields of each register are detailed in Table 29. All
four of these registers are write only.
The WUC should be configured as follows:
1.
2.
3.
4.
COUNTER
16-BIT
RELOAD VALUE
Clear all interrupts.
Set required interrupts.
Write to WUC_CONFIG_HIGH and WUC_CONFIG_
LOW. Ensure that the WUC_ARM bit = 1. Ensure that the
WUC_BBRAM_EN bit = 1 (retain BBRAM during
PHY_SLEEP). It is necessary to write to both registers
together in the following order: WUC_CONFIG_HIGH
directly followed by writing to WUC_CONFIG_LOW.
Write to WUC_VALUE_HIGH and WUC_VALUE_LOW.
This configures the WUC_TIMER_VALUE[15:0] and,
thus, the WUC timeout period. The timer begins counting
from the configured value after these registers have been
written to. It is necessary to write to both registers together
in the following order: WUC_VALUE_HIGH directly
followed by writing to WUC_VALUE_LOW.
WUC_VALUE_LOW
TO FIRMWARE TIMER
32.768 kHz Divider
1
4
8
16
128
1034
8192
65,536
WAKE-UP CIRCUIT
ADF7023-J
2
(
WUC_PRESCA
WUC_TIMEOUT
INTERRUPT
Tick Period
30.52 μs
122.1 μs
244.1 μs
488.3 μs
3.91 ms
31.25 ms
250 ms
2000 ms
32,768
LER
+
1)