Datasheet

AD9548 Data Sheet

Rev. E | Page 70 of 112

SERIAL PORT CONFIGURATION (REGISTER 0x0000 TO REGISTER 0x0005)

Table 37. Serial Configuration

Address Bits Bit Name Description

0x0000 [7] Unidirectional Select SPI port SDO pin operating mode.

0 (default) = 3-wire.

1 = 4-wire (SDO pin enabled).

[6] LSB first Bit order for SPI port.

0 (default) = most significant bit and byte first.

1 = least significant bit and byte first.

[5] Soft reset Device reset (invokes an EEPROM download if M[7:3] ≠ 0).

0 (default) = normal operation.

1 = reset.

[4] Long instruction 16-bit mode (the only mode supported by the device). This bit is read only and reads back as Logic

[0] Unused

Table 38. Reserved Register

Address Bits Bit Name Description

0x0001 [7:0] Unused

Table 39. Silicon Revision Level (Read Only)

Address Bits Bit Name Description

0x0002 [7:0] Reserved Default = 0xC6 = 0b11000110

Table 40. Device ID (Read Only)

Address Bits Bit Name Description

0x0003 [7:0] Reserved Default = 0x48 = 0b01001000

Table 41. Register Readback Control

Address Bits Bit Name Description

0x0004 [7:1] Unused

0 Read buffer register For buffered registers, serial port readback reads from actual (active) registers instead

of from the buffer.

0 (default) = reads values currently applied to the internal logic of the device.

1 = reads buffered values that take effect on the next assertion of the I/O update.

Table 42. Soft I/O Update

Address Bits Bit Name Description

0x0005 [7:1] Unused

0 I/O update Writing a 1 to this bit transfers the data in the serial I/O buffer registers to the

internal control registers of the device. This is an autoclearing bit.