
Philips Semiconductors
PNX15xx Series
Volume 1 of 1
Chapter 8: General Purpose Input Output Pins
PNX15XX_SER_3
Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Product data sheet
Rev. 3 — 17 March 2006
8-17
2.5 The GPIO Clock Pins
GPIO[14:12,6:4] pins can be assigned to drive a clock generated from the clock
module. These are clocks generated by DDS clock generators.
Table 4 shows the
mapping between DDS clocks and the GPIO pins through which they are routed to.
The clocks on pins 4, 5 and 6 can be used as clock sources for the FIFO queues. In
this case the clocks are rst routed to the pins, GPIO[4], GPIO[5] and GPIO[6], and
then brought back inside the chip as any other external clock source would be. To use
this feature the GPIO_EV register should be programmed in the following way:
GPIO_EV.EN_CLOCK_SEL = enabled, i.e. set to binary code 01 or 11
GPIO_EV.EN_DDS_SOURCE = enabled, i.e. set to ‘1’.
GPIO_EV.CLOCK_SEL = select between pins 4, 5 or 6
The clocks are selectable individually.
The clocks on pins 12, 13 and 14 are only routed to the PNX15xx Series pins and can
be used as clock sources for some external devices, or loop back on the system
board to GPIO[3:0]. They are not directly used as internal clock sources for the FIFO
queues. In order to route the clocks on these GPIO[14:12] pins, the DDS_OUT_SEL
MMIO register should be programmed appropriately.
2.6 GPIO Interrupts
Each operating FIFO queue can generate 4 types of interrupts:
BUF2_READY: DMA buffer 2 ready for reading or writing
FIFO_OE: DMA buffer overrun error
INT_OE: Internal buffering overrun error.
Each timestamp unit has 2 types of interrupts:
DATA_VALID: TSU has data ready to be read
INT_OE: Internal buffering overrun error
Each FIFO queue has its own interrupt line to the TM3260 CPU, see
Table 5 onTable 4: GPIO clock sources
GPIO[x] pin
Possible Clock Source
14
DDS0 or DDS2 (The selection is made in the clock module)
13
DDS5 or DDS1 (The selection is made in the clock module)
12
DDS6
6
DDS6
5
DDS7
4
DDS8