UPD77533 datasheet(33/104 Pages) RENESAS

33 / 104 page

Data Sheet S15671EJ4V0DS

µµµµPD77533

6.3

RF Power Supply Control

The RF Power Control command (CMD-ID: 0x05) is used to control the power supply of the RF block.

During positioning (while the GPS signal is being received), control from the host CPU via this command is not

required because the

µPD77533 autonomously controls the RF block at this time.

6.4

TXACTV Control

The TXACTV Control command (CMD-ID: 0x07) is used to set mask control of the A/D conversion value via

TXACTV pin input.

Figure 6-1. TXACTV Control

The

µPD77533 has a function to mask the A/D converter output value by 0H in cases such as when the GPS

receive signal is degraded due to noise at the PDC/PHS RF output, or other such noise. The initial setting is “A/D

conversion value unmasked”.

When a signal indicating that PDC/PHS signal transmission is in progress is input to the TXACTV pin and

TXACTV control is set to “A/D conversion value masked” (TXACTV input signal = 1; PDC/PHS transmitting), the

signal received in the

µPD77533 is handled as 0b0000 regardless of the contents of the A/D converter output value

(value input to the ADDI3 to ADDI0 pins) (in other words, the A/D conversion value is masked). At the same time, the

output of the AGC and DCOFF pins becomes high-impedance.

See 5.2.1 AGC and DCOFF output signals for the relationship between the TXACTV signal input and

AGC/DCOFF pin output.

PD77533

Host CPU

Input to TXACTV

pin enabled

TXACTV Control (control used)

UPD77533 bảng dữ liệu(PDF) 33 Page - Renesas Technology Corp