Refer to the PDF data sheet for device specific package drawings
Table 8-1 describes the device configuration pins. The logic level is latched at power-on reset to determine the device configuration. The logic level on the device configuration pins can be set by using external pullup or pulldown resistors or by using some control device (for example, FPGA/CPLD) to intelligently drive these pins. When using a control device, ensure there is no contention on the lines when the device is out of reset. The device configuration pins are sampled during power-on reset and are driven after the reset is removed. To avoid contention, the control device must stop driving the device configuration pins of the DSP. And when driving by a control device, the control device must be fully powered and out of reset and driving the pins before the DSP can be taken out of reset.
Most of the device configuration pins are shared with other function pins (LENDIAN/GPIO, BOOTMODE[12:0]/GPIO[13:1], PCIESSMODE[1:0]/GPIO[15:14], and PCIESSEN/TIMI0). Some time must be given following the rising edge of reset to drive these device configuration input pins before they assume an output state (those GPIO pins should not become outputs during boot). Also be aware that systems using TIMI0 (the pin shared with PCIESSEN) as a clock input must assure that the clock is disabled from the input until after reset is released and a control device is no longer driving that input.
If a configuration pin must be routed out from the device and it is not driven (Hi-Z state), the internal pullup or pulldown (IPU/IPD) resistor should not be relied upon. TI recommends the use of an external pullup or pulldown resistor. For more detailed information on pullup or pulldown resistors and situations in which external pullup or pulldown resistors are required, see Section 8.4.
|CONFIGURATION PIN||PIN NO.||IPD/IPU(1)||FUNCTIONAL DESCRIPTION|
|LENDIAN(1)(2)||T25||IPU||Device endian mode (LENDIAN).
|BOOTMODE[12:0](1)(2)||R25, R23, U25, T23, U24, T22, R21, U22, U23, V23, U21, T21, V22||IPD||Method of boot.
Some pins may not be used by bootloader and can be used as general purpose config pins. See Bootloader for the C66x DSP User's Guide for how to determine the device enumeration ID value.
|PCIESSMODE[1:0](1)(2)||W21, V21||IPD||PCIe Subsystem mode selection. (C6654 Only)
|PCIESSEN(1)(2)||AD20||IPD||PCIe subsystem enable/disable.
(C6654 Only - this pin must return low during reset on C6652 devices)
(For C6652 devices, this pin must return low during reset.)
For proper C6652 device operation, this pin must be low during reset.