LH79524/LH79525 User’s Guide
Analog-to-Digital Converter/Brownout Detector
Version 1.0
2-11
2.2.2 Register Descriptions
2.2.2.1 High Word Register (HW)
HW is the High Word Register. This Read Only status register shows the contents of the
current conversion’s high word in the control bank. There is a one-to-one correspondence
between the contents of the control bank high word and the contents of this register for the
current conversion in progress.
Table 2-2. HW Register
BIT
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
FIELD
///
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RW
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
FIELD
SETTIME
INP
INM
REFP
RESET
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
RW
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
ADDR
0xFF 0x00
Table 2-3. HW Fields
BITS
NAME
DESCRIPTION
31:16
///
Reserved
Reading returns 0. Write the reset value.
15:7
SETTIME
Number of Clock Cycles
Specifies the number of clock cycles that the ADC
allows for the input signal to settle to within required accuracy before beginning
conversion. Used with bits [10:8] of the PC Register to set the acquire time in
clock cycles (see Section 2.2.2.5).
For example, if Frequency In (ƒIN) = 2 MHz (500 ns period):
PC[10:8] = 010 (i.e., divide ƒIN by 4)
HW[15:6] = 000100000 (i.e., 32 cycles)
Therefore, acquire time is 500 ns × 4 × 32 = 64
μ
s
6:3
INP
In+ Mux
Determines the signal connected to the positive input of the ADC.
2
INM
In- Mux
Determines the signal connected to the negative input of the ADC.
1 = GND
0 = Ref- (output of the Ref- Mux)
1:0
REFP
Ref+ Mux
Determines the signal connected to the positive reference of the ADC.
00 = VREF+ (positive terminal of the internal bandgap reference)
01 = AN0 (UL/X+)
10 = AN2 (LL/ Y+)
11 = AN8