Datasheet

AFE4490
www.ti.com SBAS602F –DECEMBER 2012–REVISED OCTOBER 2013
AFE REGISTER DESCRIPTION
CONTROL0: Control Register 0 (Address = 00h, Reset Value = 0000h)
D23 D22 D21 D20 D19 D18 D17 D16 D15 D14 D13 D12
0 0 0 0 0 0 0 0 0 0 0 0
D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
TIM_
SPI_
0 0 0 0 0 0 0 0 SW_RST DIAG_EN COUNT_
READ
RST
This register is write-only. CONTROL0 is used for AFE software and count timer reset, diagnostics enable, and
SPI read functions.
Bits D[23:4] Must be '0'
Bit D3 SW_RST: Software reset
0 = No action (default after reset)
1 = Software reset applied; resets all internal registers to the default values and self-clears
to '0'
Bit D2 DIAG_EN: Diagnostic enable
0 = No Action (default after reset)
1 = Diagnostic mode is enabled and the diagnostics sequence starts when this bit is set.
At the end of the sequence, all fault statuses are stored in the DIAG: Diagnostics Flag
Register. Afterwards, the DIAG_EN register bit self-clears to '0'.
Note that the diagnostics enable bit is automatically reset after the diagnostics completes
(slow =16 ms, fast = 8 ms). During diagnostics mode, the ADC data are invalid because of
toggling diagnostics switches.
Bit D1 TIM_CNT_RST: Timer counter reset
0 = Disables timer counter reset, required for normal timer operation (default after reset)
1 = Timer counters are in reset state
Bit D0 SPI READ: SPI read
0 = SPI read is disabled (default after reset)
1 = SPI read is enabled
LED2STC: Sample LED2 Start Count Register (Address = 01h, Reset Value = 0000h)
D23 D22 D21 D20 D19 D18 D17 D16 D15 D14 D13 D12
0 0 0 0 0 0 0 0 LED2STC[15:0]
D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
LED2STC[15:0]
This register sets the start timing value for the LED2 signal sample.
Bits D[23:16] Must be '0'
Bits D[15:0] LED2STC[15:0]: Sample LED2 start count
The contents of this register can be used to position the start of the sample LED2 signal with
respect to the pulse repetition period (PRP), as specified in the PRPCOUNT register. The
count is specified as the number of 4-MHz clock cycles. Refer to the Using the Timer
Module section for details.
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