2.0 Programming Description

2.1 MICROWIRE INTERFACE

The LMX2324 register set can be accessed through the MICROWIRE interface. A 18-bit shift register is used as a temporary reg-

ister to indirectly program the on-chip registers. The shift register consists of a 17-bit DATA[16:0] field and a 1-bit address (ADDR)

field as shown below. The address field is used to decode the internal register address. Data is clocked into the shift register in

the direction from MSB to LSB, when the CLOCK signal goes high. On the rising edge of Load Enable (LE) signal, data stored

in the shift register is loaded into the addressed latch.

MSB

LSB

DATA[16:0]

ADDR

17

1

0

2.1.1 Registers’ Address Map

When Load Enable (LE) is transitioned high, data is transferred from the 18-bit shift register into the appropriate latch depending

on the state of the ADDRESS bit. A multiplexing circuit decodes the address bit and writes the data field to the corresponding in-

ternal register.

REGISTER

ADDRESSED

ADDRESS BIT

ADDR

R Register

1

N Register

0

www.national.com

6