link to page 4 BPSK Wireless Data Modulator CMX7146 5General Description5.1CMX7146 Features The CMX7146 is a transmit-only device for use in BPSK wireless data systems. A flexible power control facility allows the device to be placed in its powersave mode when not actively processing signals. The device includes a crystal clock generator, with buffered output, to provide a common system clock if required. A block diagram of the device is shown in Figure 1. Tx Functions: o Flexible Tx data transfer block size, up to 104bits o Root raised cosine pulse-shape filtering o RAMDAC capability for PA ramping control o Tx burst sequence for automatic RAMDAC ramp and Tx hardware switching Auxiliary Functions: o 2 programmable system clock outputs o 2 auxiliary ADCs with four selectable input paths o 4 auxiliary DACs, one with built-in programmable RAMDAC Interface: o Adjustable I/Q modulation outputs to suit CMX971 o Optimised C-BUS (4 wire high speed synchronous serial command / data bus) interface to host for control and data transfer o Open drain IRQ to host o Four GPIO pins o Flash/EEPROM boot mode o C-BUS (host) boot mode 2019 CML Microsystems Plc Page 10 D/7146/1 Document Outline Datasheet Front Page 1 Brief Description 1.1 History 2 Signal List 3 External Components 4 PCB Layout Guidelines and Power Supply Decoupling 5 General Description 5.1 CMX7146 Features 6 Detailed Descriptions 6.1 Xtal Frequency 6.2 Host Interface 6.2.1 C-BUS Operation 6.3 Function Image Loading 6.3.1 FI Loading from Host Controller 6.3.2 FI Loading from Flash/EEPROM 6.4 Device Control 6.4.1 Device Configuration (using the Programming Register) 6.4.2 Device Configuration (using dedicated registers) 6.4.3 Interrupt Operation 6.4.4 Signal Routing 6.4.5 Loading Transmit Data 6.4.6 The Transmit Sequence 6.4.7 Other Modem Modes 6.4.8 Data Transfer 6.4.9 Raw Data Transfer 6.4.10 Pre-loading transmit data 6.4.11 Auxiliary clock rates 6.4.12 Auxiliary data 6.4.13 GPIO Pin Operation 6.4.14 Auxiliary ADC Operation 6.4.15 Auxiliary DAC / RAMDAC Operation 6.5 Digital System Clock Generators 6.5.1 System Clock Operation 6.6 Signal Level Optimisation 6.7 C-BUS Register Summary 7 CMX7146 FI-1.x Features 7.1 Modulation 7.2 Radio Interface 7.3 Transmit Performance 8 Performance Specification 8.1 Electrical Performance 8.1.1 Absolute Maximum Ratings 8.1.2 Operating Limits 8.1.3 Operating Characteristics 8.1.4 Parametric Performance 8.2 C-BUS Timing 8.3 Packaging END OF DOCUMENT