Correlator Registers; Threshold Register; Table 16-40 Threshold Register Description (Mc13180) - Motorola DragonBall MC9328MX1 Reference Manual

16.5.6 Correlator Registers

Five addresses pertain to correlator functions. The Threshold Register and Correlation Max Register are
write and read registers associated with one address.

16.5.6.1 Threshold Register

The write-only Threshold Register determines when an access code is considered valid. When the radio
receives a message, the BTA calculates the correlation between the access word written to the appropriate
Synch Word X Register (see Synch Word 0 Register (Write)) and the bits in the received message. When
the correlation value exceeds the value in the Threshold Register, the access code is considered valid.
The correlation depends on the signal strength and the access code. The values written to the Threshold
Register determine the signal energy level and the threshold required to accept the access word. The signal
levels and threshold values are functions of the values written to the Threshold Register. Reading address
0x0021606C returns the Correlation Max Register (see section 16.5.6.2).
The Threshold Register bits, when used with the MC13180 radio, are explained in Table 16-40. The
Threshold Register bits, when used with the SiliconWave radio, are explained in Table 16-41.
THRESHOLD
BIT 31 30 29
TYPE r r r
0 0 0
RESET
BIT 15 14 13
TYPE r r r
0 0 0
RESET
Table 16-40. Threshold Register Description (MC13180)
Name
Reserved Reserved—These bits are reserved and should read 0.
Bits 31–8
THRESHOLD_II Signal Energy—Sets the clipping level for the access code
Bits 7–4 correlation.
THRESHOLD_I Threshold Value—Sets the threshold value for the access code
Bits 3–0 correlation.
MOTOROLA
Threshold Register (MC13180)
28 27 26 25
r r r r
0 0 0 0
12 11 10 9
r r r r
0 0 0 0
Description
Bluetooth Accelerator (BTA)
24 23 22 21 20
r r r r
0 0 0 0 0
0x0000
8 7 6 5 4
THRESHOLD_II
(MC13180)
THRESHOLD (SiliconWave)
w w w w w
1 1 1 0 0
0x01C2
Programming Model
Addr
0x0021606C
19 18 17 16
r r r r
0 0 0
3 2 1
THRESHOLD_I (MC13180)
w w w
0 0 1
Settings
Default setting is 0.5625
Default setting is 1.25
16-57
r
0
0
w
0