Analog Devices ADSP-21535 E-KIT LITE Using the Programmable Flag Pins, Flag Connected Use

3.6Using the Programmable Flag Pins

The ADSP-21535 has 16 asynchronous Programmable Flag (PF) I/O pins. During reset PF0-PF9 function as inputs to the internal PLL of the DSP. They are not valid until 120uS after reset. Table 3-3describes how the PFs are used on the EZ-KIT Lite.

After a DSP reset, all of the PF pins are initialized as inputs. The direction of the PF is configured by the FIO_DIR Memory Mapped Register (MMR). The PFs are set high (1) using the FIO_FLAG_S and cleared (0) using the FIO_FLAG_C MMRs. For more information on configuring the PF pins, see the ADSP-21535 DSP Hardware Reference Manual.

All of the PFs can are brought out to the expansion connector P2. The location of the PF nets can be found in APPENDIX B: SCHEMATIC.

Table 3-3: Programmable Flag Pin Summary

Flag	Connected	Use
	to
PF0	LED4	PF0-3 are connected to the LEDs. These can be used
PF1	LED1	to light an LED when a routine completes.
PF2	LED2
PF3	LED3
PF4	SW4	PF4-7 are connected to the push buttons on the EZ-
PF5	SW5	KIT Lite board and are for user input. Your routine
PF6	SW6	can monitor and execute specific code when a push
PF7	SW7	button has been pressed.
PF8		Not used
PF9		Not used
PF10		Not used
PF11		Not used
PF12	PMGMT0	These are used to change the internal voltage of the
PF13	PMGMT1	DSP. Refer to section 3.6.1 for more information.
PF14	PMGMT2
PF15	U7.11	Connected to the reset of the AD1885 Codec (U7).
		This signal must be output as a high (1) to enable the
		AD1885 Codec.

ADSP-21535 EZ-KIT Lite Evaluation System Manual 3-5