ATA5749_09 ATMEL [ATMEL Corporation], ATA5749_09 Datasheet - Page 14

• Manufacturer Part Number: ATA5749_09
• Description: Fractional-N PLL Transmitter IC
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 6-3.
6.3
14
Reprogramming without Stopping the Crystal Oscillator
ATA5749 [Preliminary]
SDIN_TXDIN
CLK (Output)
SCK (Input)
PA (Output
EN (Input)
Timing Diagram if Programming is Slower than T
Power)
(Input)
OFF_
Mode
Figure 6-3
gram of the operating modes is shown in
active is provided in
culation of consumed charge for one operation cycle.
After the configuration register is programmed and RF data transmission is completed, the OFF
mode is normally entered. This stops the crystal oscillator and PLL. If it is desirable to modify the
contents of the configuration register without entering the OFF mode, the Reset_Register_Mode
can be used. To enter the Reset_Register_Mode, the SDIN_TXDIN must be asserted HIGH
while the EN is asserted LOW for at least 10 µs Reset_min time. This state is shown in
6-4 on page
tional PLL remain OFF but the XTO remains active. This state must stay for minimum 10 µs. At
the next step you must rise first EN and SDIN_TXDIN 10 µs delayed. While in this mode, the
32 bit configuration register data can be sent on the SPI bus as shown in
After data transmission, the device can be switched back to OFF_Mode by asserting EN, SCK,
and SDIN_TXDIN to a LOW state. An example of programming from the Reset_Register_Mode
is shown in
Start_Up_
Mode_1
shows the combination with slow programming and a faster ramp up of XTO. A dia-
Figure 6-4 on page
15, State Diagram of Operating Modes. In Reset_Register_Mode, the PA and frac-
T
XTO
Table 6-3 on page
Start_Up_
Mode_2
32-bit Configuration
15.
XTO
15. This also contains the information needed for the cal-
Figure 6-5
Mode1
and a description of which circuit blocks are
T
TX_
PLL
X
TX_Mode1 and
TX-Data
TX_Mode2
TX_Mode2
FSK;
ASK:
X
Figure 6-2 on page
OFF_Mode
9128D–RKE–01/09
Figure
13.