Datasheet

Conversion Results Register Descriptions
The devices conversion results registers are all read-only volatile SRAM. Values are not stored in the flash memory and
the POR value for all registers is 0000h.
Table 24. Conversion Results Registers Description
READ ONLY
ADDRESS
NAME DESCRIPTION
C4h WVRUP
Bit 15 through Bit 8 holds the 8-bit value of the pulse width ratio (t
1
÷ t
2
).for the upstream
measurement. Each bit is weighted as follows:
BIT 15 BIT 14 BIT 13 BIT 12 BIT 11 BIT 10 BIT 9 BIT 8
1 0.5 0.25 0.125 0.0625 0.03125 0.015625 0.0078125
Bit 7 thru bit 0 holds the 8-bit value of the pulse width ratio (t
2
÷ t
ideal
) where t
ideal
is equal to half
the period of the Pulse Launch Frequency for the upstream measurement. Each bit is weighted
as follows:
BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
1 0.5 0.25 0.125 0.0625 0.03125 0.015625 0.0078125
The maximum value of each of these ratios is 1.9921875.
C5h Hit1UPInt
15-bit xed-point integer value of the rst hit in the upstream direction. This integer portion is
a binary representation of the number of t
4MHz
periods that contribute to the time results. The
maximum size of the integer is 7FFFh or (2
15
- 1) x t
4MHz
.
C6h Hit1UPFrac
16-bit fractional value of the rst hit in the upstream direction. This fractional portion is a binary
representation of one t
4MHz
period quantized to a 16-bit resolution. The maximum size of the
fraction is FFFFh or (2
16
- 1)/2
16
x t
4MHz
.
C7h Hit2UPInt
15-bit xed-point integer value of the second hit in the upstream direction. This integer portion
is a binary representation of the number of t
4MHz
periods that contribute to the time results. The
maximum size of the integer is 7FFFh or (2
15
- 1) x t
4MHz
.
C8h Hit2UPFrac
16-bit fractional value of the second hit in the upstream direction. This fractional portion is a
binary representation of one t
4MHz
period quantized to a 16-bit resolution. The maximum size of
the fraction is FFFFh or (2
16
- 1)/2
16
x t
4MHz
.
C9h Hit3UPInt
15-bit xed-point integer value of the third hit in the upstream direction. This integer portion is
a binary representation of the number of t
4MHz
periods that contribute to the time results. The
maximum size of the integer is 7FFFh or (2
15
- 1) x t
4MHz
.
CAh Hit3UPFrac
16-bit fractional value of the third hit in the upstream direction. This fractional portion is a binary
representation of one t
4MHz
period quantized to a 16-bit resolution. The maximum size of the
fraction is FFFFh or (2
16
- 1)/2
16
x t
4MHz
.
CBh Hit4UPInt
15-bit xed-point integer value of the fourth hit in the upstream direction. This integer portion is
a binary representation of the number of t
4MHz
periods that contribute to the time results. The
maximum size of the integer is 7FFFh or (2
15
- 1) x t
4MHz
.
CCh Hit4UPFrac
16-bit fractional value of the fourth hit in the upstream direction. This fractional portion is a binary
representation of one t
4MHz
period quantized to a 16-bit resolution. The maximum size of the
fraction is FFFFh or (2
16
- 1)/2
16
x t
4MHz
.
MAX35101 Time-to-Digital Converter with Analog Front-End
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