JAJSOQ6 May 2022 ADC3644
PRODUCTION DATA
The following sequence summarizes all the relevant registers for changing the output interface and/or enabling the decimation filter. Steps 1 and 2 must come first since the E-Fuse load reset the SPI writes, the remaining steps can come in any order.
STEP | FEATURE | ADDRESS | DESCRIPTION | |||||
---|---|---|---|---|---|---|---|---|
1 | Output Interface | 0x07 | Select the output interface format depending on resolution and output interface. | |||||
Output Resolution | DDR | 2-wire | 1-wire | 1/2-wire | ||||
14-bit | 0xA9 | 0x2B | 0x6C | 0x8D | ||||
16-bit | 0x4B | |||||||
18-bit | N/A | 0x2B | ||||||
20-bit | N/A | 0x4B | ||||||
2 | 0x13 | Load the output interface bit mapping using the E-fuse loader (0x13, D0). Program register 0x13 to 0x01, wait ~ 1ms so that bit mapping is loaded properly followed by 0x13 0x00 | ||||||
3 | 0x0A/B/C | Power down relevant CMOS output buffers to avoid contention. | ||||||
4 | 0x18 | For serial CMOS modes, DCLKIN EN (D4) needs to be enabled. | ||||||
5 | 0x19 | When using serial CMOS, configure the FCLK frequency based on bypass/decimation and number of lanes used. | ||||||
Bypass/Dec | SCMOS | FCLK
SRC (D7) | FCLK
DIV (D4) | TOG
FCLK (D0) | ||||
Bypass/ Real Decimation | 2-wire | 0 | 1 | 0 | ||||
1-wire | 0 | 0 | 0 | |||||
1/2-wire | 0 | 0 | 0 | |||||
Complex Decimation | 2-wire | 1 | 0 | 0 | ||||
1-wire | 1 | 0 | 0 | |||||
1/2-wire | 0 | 0 | 1 | |||||
6 | 0x1B | Select the output interface resolution using the bit mapper (D5-D3). | ||||||
7 | 0x1F | For serial CMOS modes, DCLKIN EN (D6) and DCLK OB EN (D4) need to be enabled. | ||||||
8 | 0x20 0x21 0x22 | When using serial CMOS, select the FCLK pattern for decimation for proper duty cycle output of the frame clock. | ||||||
Decimation | Output Resolution | 2-wire | 1-wire | 1/2-wire | ||||
Real Decimation | 14-bit | use default | 0xFE000 | use default | ||||
16-bit | 0xFF000 | |||||||
18-bit | 0xFF800 | |||||||
20-bit | 0xFFC00 | |||||||
Complex Decimation | 14-bit | 0xFFFFF | 0xFFFFF | |||||
16-bit | ||||||||
18-bit | ||||||||
20-bit | ||||||||
9 | 0x39..0x60 0x61..0x88 |
Change output bit mapping for chA and chB if desired. This works also with the default interface selection. | ||||||
10 | Decimation Filter | 0x24 | Enable the decimation filter | |||||
11 | 0x25 | Configure the decimation filter | ||||||
12 | 0x2A/B/C/D 0x31/2/3/4 | Program the NCO frequency for complex decimation (can be skipped for real decimation) | ||||||
13 | 0x27 0x2E | Configure the complex output data stream (set both bits to 0 for real decimation) | ||||||
Serial CMOS | OP-Order (D4) | Q-Delay (D3) | ||||||
2-wire | 1 | 0 | ||||||
1-wire | 0 | 1 | ||||||
1/2-wire | 1 | 1 | ||||||
14 | 0x26 | Set the mixer gain and toggle the mixer reset bit to update the NCO frequency. |