GR4x to GR64 Migration Guide
For the new variant GR64, the VREF pin is configured as an input. In this arrangement
he user provides a reference voltage from their own application, which is used by the
host-side level shifter interfaces.
Change Impact: No impact to existing users for the legacy variant.
3.2.8
Former UART2
Pin
GR64
GR4x Functional Difference
45 Reserved TD2
Migration Guide
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46 Reserved RD2
UART2 replaced by reserved interface
One of the three UARTs in the GR4x series has been replaced by a reserved interface
in the GR64. The absence of a third hardware UART encouraged this change.
Change Impact: For users of the third UART in GR4x products, some re-configuration
of serial interfaces may be necessary. Different alternatives are available; an
Embedded Application for configuring GPIO like an SPI bus offers a viable serial
interface.
3.2.9
Former PCM Audio Digital CODEC Interface
Pin
GR64
GR4x
Functional Difference
47 VUSB
PCMULD
PCM
CODEC
interface does not exist
A PCM interface between the GR4x series audio CODEC and the DSP gave users the
option of installing a DSP device to improve audio acoustic performance. The GR64
voice-band architecture is more advanced and far better performing than its
predecessor. This factor, together with the GR64 memory-mapped digital audio
removes the need for this former interface.
GR4x to GR64
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