PX5534UBJA

Instruction Sheet 408-10445 4-Wire Interface Programming Guide 14 JUL 11 Rev A Simplified Serial Shift Register IO D_IN/D_OUT 0 1 SR(N) FF SR(N-1) SR(N-2) FF FF SR1 FF SR0 FF Latch 0 1 CLK Control Latch Control Latch Control Latch Control Latch D_IN/D_OUT CLK Control Latch STB STB Figure 1 1. INTRODUCTION TE Connectivity’s Optical Driver and Receiver Integrated Circuits (ICs) provide a serial digital interface that allows internal registers to be programmed and monitored. This document describes the protocol used to read and write to the internal registers for ICs featuring the 4-Wire Digital Programming Interface. The customer drawing includes details such as internal register definitions and their default values. 2. DESCRIPTION The serial interface consists of a four-wire connection to an internal control shift register, as shown in Figure 1. The four control signals are clock (CLK), data in (D_IN), data out (D_OUT), and strobe (STB). Each control signal is intended to be connected to a microcontroller. Some ICs have an IO pad which can control the location of the D_IN and D_OUT pads. If available, the IO pad will be at pad location 1 on the customer drawing. Data is clocked into the shift register on the rising edge of CLK and is clocked out of the SR on the falling edge of CLK as shown in Figure 2. Asserting STB latches data from the shift registers into control latches. A preamble of 1010 (PREAMBLE [3:0] = 1010) is required for STB to clock data into control latches. If the preamble is incorrect, STB will not write data to the control latches and the wire registers will remain unchanged. Upon power-up of the IC, the shift registers default to a set value which are defined in the customer drawing. The shift register is segmented such that the least significant blocks of registers contain global controls. Shift register bit 0 is the first bit in time to be shifted into the register. 3. REIVISON SUMMARY • Initial release of document Serial Interface Timing Diagram Figure 2 ©2011 Tyco Electronics Corporation, a TE Connectivity Ltd. Company All Rights Reserved *Trademark TOOLING ASSISTANCE CENTER 1-800-722-1111 PRODUCT INFORMATION 1-800-522-6752 This controlled document is subject to change. For latest revision and Regional Customer Service, visit our website at www.te.com TE Connectivity, TE connectivity (logo), and TE (logo) are trademarks. Other logos, product and/or Company names may be trademarks of their respective owners. 1 of 1 LOC B