W7020 Datasheet, PDF (21/36 Pages) List of Unclassifed Manufacturers – Bluetooth Radio Module

Preliminary Data Sheet
September 2000
W7020 Bluetooth Radio Module
Serial Interface (continued)
Channel Register Programming Example
The following example demonstrates how to program the W7020 for transmit channel 50. The first step is to
point to the channel register by doing an IR-scan. The CMS signal is used to put the CAP (see Figure 7) in the
SHIFT_IR state. After the CAP is in the SHIFT_IR state, the channel address value 010010 (18) should be
shifted into the CDI input (LSB first). When the CAP returns to the RUN_TEST/IDLE state, the instruction register
is updated.
The new channel value is entered by performing a DR-scan. The CMS signal is used to put the CAP in the
SHIFT_DR state. The channel value of 50 is shifted in the CDI = 00110010 (50 decimal) LSB first. When the
CAP is returned to RUN_TEST/IDLE, the channel register is updated.
If no other W7020 register has been addressed when a new channel value is required, only a new DR-scan
needs to be done, because the IR already points to the channel register. When data is shifted in, previous data
contained in the selected register will simultaneously be shifted out on the CDO. In the case of the channel
register, the value of the RSSI will be shifted out on the CDO.
An example of programming the channel register is shown below. All input signals (CDI, CMS) to the serial
interface should change on the negative edge of the serial interface clock (CLK) to eliminate setup and hold
violations. The serial interface samples the CDI and CMS signals on the positive edge of CCK. The output
signal (CDO) changes on the negative edge. In the final application, CDO is sampled on the positive CLK edge.
CMS 1 1 1 1 1 0 1 1 0 0 0 0 0 0 0 1 1 1 0 0 0
CAP STATE SHIFT_IR
SHIFT_IR AND EXIT
UPDATE IR,
SELECT _DR
CDI X X X X X X X X X X 0 1 0 0 1 0 X X X X 0
DON’T CARE
CHANNEL REGISTER 18
CDO — — — — — — — — — — 1 0 0 1 1 0 — — — — ?
HIGH IMPEDANCE
000000
SHIFT_DR AND EXIT
100110
CHANNEL VALUE 50
??????
RSSI VALUE
11 0 0
RUN_TEST
IDLE
0XXX
? ———
Figure 7. Serial Interface Channel Register Programming Example Timing Information
Lucent Technologies Inc.
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