PLL Control Registers
535
SPNU563A – March 2018
Copyright © 2018, Texas Instruments Incorporated
Oscillator and PLL
14.6.1 PLL Modulation Depth Measurement Control Register (SSWPLL1)
illustrates this register and
provides the bit descriptions. This register applies to
PLL1, but does not apply to PLL2.
Figure 14-6. SSW PLL BIST Control Register 1 (SSWPLL1) [offset = 24h]
31
16
Reserved
R-0
15
8
CAPTURE_WINDOW_INDEX
R/W-0
7
6
5
4
3
1
0
Reserved
COUNTER_READ_
READY
COUNTER_
RESET
COUNTER_EN
TAP_COUNTER_DIS
EXT_COUNTER_
EN
R-0
R-0
R/W-1
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 14-6. SSW PLL BIST Control Register 1 (SSWPLL1) Field Descriptions
Bit
Field
Value
Description
31-16
Reserved
0
Reads return 0. Writes have no effect.
15-8
CAPTURE_WINDOW_INDEX
0-FFh
The capture counter present in the PLL wrapper will count the PLL clock edges when
the current modulation phase capture window value is equal to these bits. Should be
set equal to NR.
7
Reserved
0
Reads return 0. Writes have no effect.
6
COUNTER_READ_READY
Counter read ready.
Indicates that SSW_CAPTURE_COUNT (SSWPLL2) and SSW_CLKOUT_COUNT
(SSWPLL3) can be read.
0
Counter registers in SSWPLL2 and SSWPLL3 are not ready to read.
1
Counter registers in SSWPLL2 and SSWPLL3 are ready to read.
5
COUNTER_RESET
Counter reset.
If EXT_COUNTER_EN = 0, COUNTER_RESET resets SSW_CAPTURE_COUNT
(SSWPLL2) and SSW_CLKOUT_COUNT (SSWPLL3).
If EXT_COUNTER_EN = 1, this bit is ignored.
0
No impact to counters.
1
If the EXT_COUNTER_EN bit is 0, then counters SSW_CAPTURE_COUNT and
SSW_CLKOUT_COUNT will be held in the reset state.
If EXT_COUNTER_EN bit is 1, then this bit will be ignored by the PLL wrapper.
4
COUNTER_EN
Counter enable.
If EXT_COUNTER_EN = 0, COUNTER_EN initializes the modulation depth
measurement. (In this mode, the disable is set to occur automatically.)
If EXT_COUNTER_EN = 1, the counters are enabled/disabled with COUNTER_EN.
0
If EXT_COUNTER_EN = 0, COUNTER_EN = 0 indicates that the counters are
inactive.
If EXT_COUNTER_EN = 1, COUNTER_EN = 0 disables the counters.
1
If EXT_COUNTER_EN = 0, COUNTER_EN = 1 indicates that the counters are still
active.
If EXT_COUNTER_EN = 1, COUNTER_EN = 1 enables the counters.