Si4020
9. Wake-Up Timer Command
bit
15
1
14
1
13
1
12
r4
11
r3
10
r2
9
8
7
6
5
4
3
2
1
0
POR
r1
r0
m7 m6
m5 m4 m3 m2 m1 m0
E000h
The wake-up time period can be calculated as:
Twake-up = M * 2R [ms] ,
where M is defined by the <m7 : m0> digital value and R is defined by the <r4 : r0> digital value.
The value of R should be in the range of 0 and 23. The maximum achievable wake-up time period can be up to 24 days.
Note:
• For continual operation the et bit should be cleared and set at the end of every cycle.
Software reset: Sending FF00h command to the chip triggers software reset. For more details see the Reset modes section.
10. Data Transmit Command
This command is not needed if the transmitters’ power management bits (ex, es, ea) are fully controlled by the microcontroller and
TX data comes through the FSK pin.
In EEPROM operation mode:
bit
15
1
14
1
13
0
12
0
11
0
10
1
9
1
8
0
7
6
5
4
3
2
1
0
POR
- -
n7
n6
n5
n4
n3
n2
n1
n0
In microcontroller slave mode:
bit
7
1
6
1
5
0
4
0
3
0
2
1
1
1
0
0
POR
- -
This command indicates that the following bitstream coming in via the serial interface is to be transmitted. In EEPROM mode, the 8-
bit value N of bits <n7 : n0> contains the number of data bytes to follow.
Note:
• If the crystal oscillator was formerly switched off (ex=0), the internal oscillator needs tsx time, to switch on. The actual value
depends on the type of quartz crystal used.
• If the synthesizer was formerly switched off (es=0), the internal PLL needs tsp startup time. Valid data can be transmitted only when
the internal locking process is finished.
• In EEPROM mode, before issuing the Data Transmit Command, the power amplifier must be enabled, with the ea or a0 bit in the
Power Management Command.
• In EEPROM mode, when N bytes have been read and transmitted the controller continues reading the EEPROM and processing the
data as control commands. This process stops after Sleep Command has been read from the EEPROM.
18
SILICON [ SILICON ]
