
Philips Semiconductors
PNX15xx Series
Volume 1 of 1
Chapter 5: The Clock Module
PNX15XX_SER_3
Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Product data sheet
Rev. 3 — 17 March 2006
5-48
5
fgpo_output_enable_n
R/W
1
FGPO output enable
0: output, the clock is generated internally
1: input, the clock is provided by an external source. Note: during
and after reset the xtal clock is forced onto the fgpo clock. In order
to actually allow the input clock to go to the fgpo this register must
be written to. This also implies that writing fgpo_output_enable_n =
1 overrides a sel_fgpo_clk = 0.
4:3
sel_clk_fgpo_src
R/W
00
00: clk_fgpo_src = PLL1
01: clk_fgpo_src = UNDEF
10: clk_fgpo_src = DDS2
11: clk_fgpo_src = clk_tm (It is not meant to be used in normal
operating mode. The observation is after the output of the duty cycle
stretcher, therefore it is the clock that feeds the TM3260).
2:1
sel_clk_fgpo
R/W
00
The following 4 settings are valid when fgpo_output_enable_n = 0
(either of the two output modes).
00: clk_fgpo = 27 MHz xtal_clk
01: clk_fgpo = clk_fgpo_src
10: clk_fgpo = clk_fgpo_src
11: clk_fgpo = LAN_RXD[2]
The following 3 settings are valid when fgpo_output_enable_n = 1
(the input mode).
01: clk_fgpo = VDO_CLK2
0
en_clk_fgpo
R/W
1
1: enable clk_fgpo
Offset 0x04,7418
CLK_FGPI_CTL
31:6
Reserved
R/W
-
To ensure software backward compatibility unused or reserved bits
must be written as zeros and ignored upon read.
5
turn_off_ack
R
0
0 - Indicates if the enabled clock is running
1 - Indicates that the clock is being blocked during a frequency
change to avoid glitches
4
fgpi_output_enable_n
R/W
1
Fgpi output enable
0: output, the clock is generated internally
1: input, the clock is provided by an external source unless
sel_fgpi_clk is 00 then it is xtal clock.
3
sel_clk_fgpi_src
R/W
0
0: clk_fgpi_src = DDS3
1: clk_fgpi_src = DDS8
2:1
sel_clk_fgpi
R/W
00
00: clk_fgpi = 27 MHz xtal_clk (voids fgpi_output_enable_n)
Only used when fgpi_output_enable_n = 0 :
01: clk_fgpi = clk_fgpi_src
10: clk_fgpi = clk_fgpi_src
11: clk_fgpi = LAN_RXD[3]
0
en_clk_fgpi
R/W
1
1: enable clk_fgpi
Offset 0x04,741C-0x04,74FCReserved
Debug Registers
Offset 0x04,7500
CLK_STRETCHER_CTL
Table 11: CLOCK MODULE REGISTERS …Continued
Bit
Symbol
Acces
s
Value
Description