A N 3 3 2
150
Rev. 0.8
Property 0x0202. REFCLK_PRESCALE
Sets the number used by the prescaler to divide the external RCLK down to the internal REFCLK. The range may
be between 1 and 4095 in 1 unit steps. For example, an RCLK of 13 MHz would require a prescaler value of 400 to
divide it to 32500 Hz. The reference clock frequency property would then need to be set to 32500 Hz. The RCLK
must be valid 10 ns before sending and 20 ns after completing the AM_TUNE_FREQ and AM_SEEK_START
commands. In addition, the RCLK must be valid at all times for proper AFC operation. The RCLK may be removed
or reconfigured at other times. The CTS bit (and optional interrupt) is set when it is safe to send the next command.
This property may only be set or read when in powerup mode. The default is 1.
Available in: All
Default: 0x0001
Step: 1
Range: 1–4095
*Note:
For shortwave frequencies, choose a prescalar value such that you can limit the REFCLK frequency range to 31130–
32768* Hz.
Bit
Name
Function
15:0
REFCLKF[15:0]
Frequency of Reference Clock in Hz.
The allowed REFCLK frequency range is between 31130 and 34406 Hz (32768
5%), or 0 (to disable AFC).
Bit
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Name
0
0
0
RCLK
SEL
RCLKP[11:0]
Bit
Name
Function
15:13
Reserved
Always write to 0.
12
RCLKSEL
RCLKSEL.
0 = RCLK pin is clock source.
1 = DCLK pin is clock source.
11:0
RCLKP[11:0]
Prescaler for Reference Clock.
Integer number used to divide the RCLK frequency down to REFCLK frequency.
The allowed REFCLK frequency range is between 31130 and 34406* Hz (32768
±5%), or 0 (to disable AFC).