Datasheet

AD9979
Rev. C | Page 23 of 56
COMPLETE FIELD—COMBINING H-PATTERNS
After creating the H-patterns, they combine to create different
readout fields. A field consists of up to nine different regions
determined by the SCP registers, and within each region, a
different H-pattern group can be selected, up to a maximum of
32 groups. Registers to control the H-patterns are located in the
field registers. Table 13 describes the field registers.
H-Pattern Selection
The H-patterns are stored in the HPAT memory, as described in
Table 33. The user decides how many H-pattern groups are
required, up to a maximum of 32, and then uses the HPAT_SELx
registers to select which H-pattern group is output in each
region of the field. Figure 32 shows how to use the HPAT_SELx
and SCPx registers. The SCPx registers create the line
boundaries for each region.
VD
REGION 0
FIELD SETTINGS:
1. SEQUENCE CHANGE POSITIONS (SCP0 TO SCP8) DEFINE EACH OF THE NINE AVAILABLE REGIONS IN THE FIELD.
2. HPAT_SEL SELECTS THE DESIRED H-PATTERN FOR EACH REGION.
H-PATTERNS
HD
SCP 1 SCP 2
HPAT_SEL0 HPAT_SEL1
S
C
P3
HPAT_SEL2
S
C
P4
HPAT_SEL3
S
C
P5
HPAT_SEL4
S
C
P8
HPAT_SEL8
REGION 1 REGION 2 REGION 3 REGION 4 REGION 8
SCP 0
05957-034
Figure 32. Complete Field Divided into Regions
Table 13. Field Registers
Name Length Range Description
SCPx 13 bits 0 to 8191 line number Sequence change position for each region; selects an individual line
HPAT_SELx 5 bits 0 to 31 H-patterns Selected H-pattern for each region of the field
CLPOB_POL 9 bits High/low CLPOB start polarity settings for each region of the field
CLPOB_PAT 9 bits 0 to 9 patterns CLPOB pattern selector for each region of the field
CLPOBMASKSTARTx,
CLPOBMASKENDx
13 bits Number of lines CLPOB mask positions for up to three masking configurations
PBLK_POL 9 bits High/low PBLK start polarity settings for each region of the field
PBLK_PAT 9 bits 0 to 9 patterns PBLK pattern selector for each region of the field
PBLKMASKSTARTx,
PBLKMASKENDx,
13 bits Number of lines PBLK mask positions for up to three masking configurations