Visible to Intel only — GUID: zej1616508698887
Ixiasoft
Visible to Intel only — GUID: zej1616508698887
Ixiasoft
3.6.4. FGT PMA Fractional Mode
Fo a give data ate, the dop-dow meu lists the suppoted itege mode efeece clock fequecies. Fo a give data ate, if the equied efeece clock fequecy is ot listed i the dop-dow, you ca eithe select oe of the suppoted itege mode efeece clock fequecies o eable factioal mode.
- Whe eablig factioal mode, Altea ecommeds usig 141 MHz efeece clock fequecy to maximize the distace o the PLL spus acoss all OTN / SDI / CPRI ates.
-
VCO fequecy (MHz) = (M + k/2^22) * mul_div * efclk fequecy (MHz) / N
-
Output fequecy (MHz) = VCO fequecy (MHz) / L
Whe the factioal PLL efeece clock fequecy is eteed, the IP GUI displays the VCO, M, N, L, k, ad mul_div values i the System Messages tab as show i the followig figue.
- Fo a give data ate, you must eable factioal mode if you eed to dyamically cofigue the k coute duig u time.
FGT PMA suppots factioal mode i followig PMA modes:
PMA Mode | Factioal Mode Suppot |
---|---|
TX simplex | TX FGT PLL suppots factioal mode i TX simplex. To eable, select TX simplex optio fo PMA mode, ad tu o the Eable TX FGT PLL factioal mode i the paamete edito. The TX PLL factioal coute values automatically calculate fo the selected efeece clock fequecy. You ca place TX Simplex factioal mode o ay of 16 FGT TX PMAs.
Note: FGT PMA does ot suppot factioal mode fo RX simplex.
|
Duplex | FGT PMA i Duplex PMA mode suppots factioal mode. To eable factioal mode i duplex PMA mode, select the Duplex optio fo PMA mode, select up to 16 fo the Numbe of PMA laes, ad tu o Eable TX FGT PLL factioal mode optio i the paamete edito.
|
Pimay PLL cofiguatio | To eable factioal mode with the pimay PLL cofiguatio, select the Duplex optio fo PMA mode, select 2 o 4 fo the Numbe of PMA laes, ad tu o Eable TX FGT PLL factioal mode ad Eable TX FGT PLL cascade mode optios i the paamete edito.
|
Tuig the k Coute Value i Factioal Mode
- Whe umbe of PMA laes is 1, tu o Eable TX FGT PLL factioal mode, set PMA efeece clock fequecy as 141 MHz, ad tue the k coute value of the lae.
- Whe umbe of PMA laes is 2, o 4, tu o Eable TX FGT PLL factioal mode, tu o Eable TX FGT PLL cascade mode, set PMA efeece clock fequecy as 141 MHz, ad tue the k coute value of the pimay lae.
- Maximum step size: 2.5 ppm
- Miimum duatio betwee steps: 1 us
- Maximum step size: 100 ppm
- Miimum duatio betwee steps: ukow
Each FGT PMA has a Avalo® memoy-mapped iteface egiste cotaiig the k coute. The k coute / 2^22 gives the factioal value K of the feedback coute. The factioal value K plus the M coute value povides the total feedback coute ad detemies how much PPM each bit i the k coute epesets. Fo example, the LSB (least sigificat bit) i the k coute epesets PPM = (1 / 2^22) / (K+M) × (10^6).
The pocedue to chage the k coute is:
- Chage the k coute to the ew value.
- Pulse the stobe bit 0 -> 1-> 0 to lock i the ew k coute.
Each FGT PMA cotais 3 PLLs; slow, medium ad fast. FGT PMAs ae ogaized i a quad. The k coute ad stobe bit Avalo® memoy-mapped iteface egiste addesses deped o the locatio of the tasceive i the quad ad which PLL is used (slow, medium, fast) as show i the table below.
Chael Locatio i Quad | PLL | Factioal k Coute Registe | Stobe Registe |
---|---|---|---|
0 | Slow | 0x44000[30:9] | 0x4400C[17] |
Medium | 0x44100[30:9] | 0x4410C[17] | |
Fast | 0x44200[30:9] | 0x4420C[17] | |
1 | Slow | 0x4C000[30:9] | 0x4C00C[17] |
Medium | 0x4C100[30:9] | 0x4C10C[17] | |
Fast | 0x4C200[30:9] | 0x4C20C[17] | |
2 | Slow | 0x54000[30:9] | 0x500C[17] |
Medium | 0x54100[30:9] | 0x5410C[17] | |
Fast | 0x54200[30:9] | 0x5420C[17] | |
3 | Slow | 0x5C000[30:9] | 0x5C00C[17] |
Medium | 0x5C100[30:9] | 0x5C10C[17] | |
Fast | 0x5C200[30:9] | 0x5C20C[17] |
; z1577a_u_ux_quad_3__ux3_syth_lc_med_e ; eable ; Stig ; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_f_out_hz ; 0000000001010110011011010011111010000000 ; Usiged Biay; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_f_pfd_hz ; 0000000000000000000000000000000000000000 ; Usiged Biay; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_f_ef_hz ; 0000000000001000110110011110111000100000 ; Usiged Biay; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_f_x_postdiv_hz ; 0000000000010001010010010000110010000000 ; Usiged Biay; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_f_tx_postdiv_hz ; 0000000000000110111010100000010100000000 ; Usiged Biay; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_f_vco_hz ; 0000001010110011011010011111010000000000 ; Usiged Biay; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_factioal_e ; eable ; Stig ; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_k_coute ; 0000111010100111001110 ; Usiged Biay; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_l_coute ; 001000 ; Usiged Biay; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_m_coute ; 000100111 ; Usiged Biay; ; z1577a_u_ux_quad_3__ux3_syth_lc_med__coute ; 000001 ; Usiged Biay; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_powedow_mode ; false ; Stig ; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_pimay_use ; ux3_syth_lc_med_pimay_use_disabled ; Stig ; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_x_postdiv_coute ; 00101000 ; Usiged Biay; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_tx_postdiv_coute ; 01100100 ; Usiged Biay; ; z1577a_u_ux_quad_3__ux3_syth_lc_med_tx_postdiv_factioal_e ; disable ; Stig ;