Datasheet

Data Sheet AD9557
Rev. B | Page 69 of 92
Table 52. IRQ Mask for Reference Inputs
Address Bits Bit Name Description
0x020E
7 Reserved Reserved
6
REFB validated Enables IRQ for indicating that REFB has been validated
5
REFB fault cleared
Enables IRQ for indicating that REFB has been cleared of a previous fault
4 REFB fault Enables IRQ for indicating that REFB has been faulted
3
Reserved Reserved
2 REFA validated Enables IRQ for indicating that REFA has been validated
1
REFA fault cleared Enables IRQ for indicating that REFA has been cleared of a previous fault
0
REFA fault Enables IRQ for indicating that REFA has been faulted
0x020F
[7:0] Reserved Reserved
Table 53. Watchdog Timer 1
1
Address Bits Bit Name Description
0x0210
[7:0] Watchdog timer (ms) Watchdog timer bits[7:0] Default: 0x00
0x0211 [7:0] Watchdog timer bits[15:8] Default: 0x00
1
Note that the watchdog timer is expressed in units of milliseconds (ms). The default value is 0 (disabled).
DPLL CONFIGURATION (REGISTER 0x0300 TO REGISTER 0x032E)
Table 54. Free Run Frequency Tuning Word
1
Address Bits Bit Name Description
0x0300
[7:0] 30-bit free run frequency tuning word Free run frequency tuning word bits[7:0]; default: 0x11
0x0301
[7:0] Free run frequency tuning word bits[15:8]; default: 0x15
0x0302
[7:0] Free run frequency tuning word bits[23:9]; default: 0x64
0x0303
[7:6] Reserved Reserved
[5:0]
30-bit free run frequency word
Free run frequency tuning word bits[29:24]: default: 0x1B
1
Note that the default free run tuning word is 0x1B641511, which is used for 8 kHz/19.44 MHz = 622.08 MHz translation.
Table 55. Digital Oscillator Control
Address Bits Bit Name Description
0x0304
[7:6]
Reserved
Default: 00b
5 DCO 4-level output 0 (default) = DCO 3-level output mode
1 = enables DCO 4-level output mode
4 Reserved Reserved (must be set to 1b)
[3:0]
Reserved Reserved (default: 0x0)