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3 page 
www.ti.com SERIAL INTERFACE Serial Interface Operation Requirement Serial Interface Device Address SCAS823 – DECEMBER 2006 Table 1. TERMINAL FUNCTIONS TERMINAL TYPE DESCRIPTION NAME NO. BYPASS 14 Input If 0, the PLL is bypassed and the PLL is switched off. CLK0 27 Output Output for Clock0 CLK0B 26 Output Complementary output for Clock0 CLK1 24 Output Output for Clock1 CLK1B 23 Output Complementary output for Clock1 CLK2 20 Output Output for Clock2 CLK2B 19 Output Complementary output for Clock2 CLK3 17 Output Output for Clock3 CLK3B 16 Output Complementary output for Clock3 EN 11 Input Output enable; if 0, all outputs are disabled. ID0 12 Input Device ID, bit 0 ID1 13 Input Device ID, bit 1 ISET 3 Output Set clock driver current with external resistor REFCLK 5 Input Reference clock input REFCLKB 6 Input Complementary reference clock input SCL 9 Input Serial interface clock, 3.3-V compatible SDA 10 Input Serial interface data, 3.3-V compatible VDD 15, 22, 28 Power 2.5-V power supply for outputs VDDC 7 Power 2.5-V power supply for core VDDP 1 Power 2.5-V power supply for PLL VSS 4, 18, 21, 25 Ground Ground VSSC 8 Ground Ground for core VSSP 2 Ground Ground for PLL The following section describes the serial interface programming. In general, the serial interface slave supports byte-write/-read and word-write/-read protocol as defined in the SMBus or I2C specification. The internal timing of the serial interface logic block in the CDCD5704 requires a timing reference derived from the input clock (REFCLK). A reference clock must be present at the REFCLK pin for the serial interface to be operational. A6 A5 A4 A3 A2 A1 A0 W/R 1 1 0 1 1 ID1 ID0 0/1 The device-ID is determined by the external pins ID0 and ID1. They are part of the device 8-bit address. Therefore, four different devices (00, 01, 10, and 11) can be addressed via the same serial interface. The least significant bit of the address designates a write or read operation. R/W Bit: 0 = write to CDCD5704 device 1 = read from CDCD5704 device 3 |
