Peripherals

TN0108

12/26

Doc ID 15874 Rev 2

5.2

ADC register map change

The ADC memory map and register description has fundamentally changed between

Cut 1.1 and Cut 2 devices. This was to bring the ADC implementation more in-line with the

format of other peripherals (for example including a Module Configuration Register).

Migrating ADC code between Cut 1.1 and Cut 2 requires a code re-write to use the new

register and bit field names. There is a new header file available to support the new interface

on Cut 2.

There are also some functional changes to the ADC going from Cut 1.1 to Cut 2 that are

detailed in the next three sections.

5.3

ADC additional external result registers

The ADC has four external channels ANX[0..3]. These can be used with four external 8-bit

multiplexers (controlled by the MA[0..2] bits) to provide up to 32 extended ADC channels.

Cut 1.1 devices have a single result register for each of the four external ADC channels.

On Cut 2 devices, there are 32 external results registers, so there is a unique results

register for each supported external channel. The results are automatically stored in the

appropriate external channel, thus allowing the user to treat an externally multiplexed

channel in the same manner as an internal channel.

Table 9.

RGM_DERD and RGM_FERD write-once protection

Silicon revision

External multiplexed channels

Implications

SPC560B Cut 1.1

Four results registers, one per ANX[0..3]

channel.

Need to read result register before

another channel on same external

multiplexer is used again.

SPC560B Cut 2

32 results registers, one for each potential

externally multiplexed channel.

External ADC channels can be treated

the same as internal channels in

software.