GC4114 Datasheet, PDF (25/45 Pages) Texas Instruments – QUAD TRANSMIT CHIP

GC4114 QUAD TRANSMIT CHIP
DATA SHEET REV 1.0
5.12 CHANNEL INPUT REGISTERS
Addresses 16 through 31 are used to input values into the chip when the channels are in the parallel input
mode. The inputs are 16 bit two’s complement numbers which are loaded as two 8 bit bytes. The address
assignments are:
ADDRESSES NAME
16,17
18,19
20,21
22,23
Channel A, I-input
Channel A, Q-input
Channel B, I-input
Channel B, Q-input
These are all read/write registers.
ADDRESSES
24,25
26,27
28,29
30,31
NAME
Channel C, I-input
Channel C, Q-input
Channel D, I-input
Channel D, Q-input
5.13 PAGE ZERO (CHANNEL CONTROL) REGISTERS
Addresses 32 to 63 are used to load each channel’s frequency, phase and gain settings when PAGE = 0 in
the status register (see Section 5.10). The address assignments are:
ADDRESSES NAME
32,33,34,35
36,37
38
39
40,41,42,43
44,45
46
47
FREQ_A[31:0]
PHASE_A[15:0]
GAIN_A[7:0]
unused
FREQ_B[31:0]
PHASE_B[15:0]
GAIN_B[7:0]
unused
ADDRESSES NAME
48,49,50,51
52,53
54
55
56,57,58,59
60,61
62
63
FREQ_C[31:0]
PHASE_C[15:0]
GAIN_C[7:0]
unused
FREQ_D[31:0]
PHASE_D[15:0]
GAIN_D[7:0]
unused
The 32 bit frequency control words (FREQ_A, FREQ_B, FREQ_C and FREQ_D) are defined as:
FREQ = 2³²F/F_CK
where F is the desired center frequency of the channel and F_CK is the chip’s clock rate (not the CK2X rate). Use
negative frequency vales to invert the signal’s spectrum. The 32 bit frequency words are entered as four bytes, the
least significant byte in the lowest address, the most significant in the higher address.
The 16 bit phase offsets are defined as:
PHASE = 2¹⁶P/2π
where P is the desired phase in radian from 0 to 2π.
The 8 bit gain is defined as:
GAIN = G/128
where G ranges from -128 to +127. Note that GAIN is only part of the chip’s gain and should be used in conjunction
with SCALE, BIG_SCALE, COARSE and SUM_SCALE. See Section 3.7 for details.
The channel control registers are read/write.
Texas Instruments Inc.
- 21 -
MAY 22, 2000
This document contains information which may be changed at any time without notice