The ramp test pattern allows the host
to specify a digital ramp that is output by the ADS921x. Configure the registers in bank 1 to enable the ramp test pattern:
- Configure the increment value
between two successive steps of the digital ramp in the RAMP_INC_CHA
(address = 0x13) and RAMP_INC_CHB (address = 0x18) registers, respectively.
The digital ramp increments by N + 1, where N is the value configured in
these registers.
- Set TEST_PAT_EN_CHA = 1,
TEST_PATMODE_CHA = 2 (address = 0x13) and TEST PAT_EN_CHB = 1,
TEST_PATMODE_CHB = 2 (address = 0x18).
The ADS921x outputs digital ramp values in place of the ADC A and ADC B data,
respectively.