User Manual

Apollo3 Blue Datasheet
DS-A3-0p9p1 Page 393 of 909 2019 Ambiq Micro, Inc.
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A variety of pads may be used for up to four nCE signals to select up to four separate slaves. The nCE
signals are pre-muxed into a signal group called NCE. The muxing configuration is shown in Table 564.
The PADnINPEN and PADnPULL bits of any pad used for nCE should be cleared.
11.5.1.11IO Master 4 4-wire SPI Connection
Four-wire SPI mode of IO Master 4 uses pad 39 as SCK, pad 40 as MISO and pad 44 as MOSI. This mode
is configured by setting the PADnFNCSEL fields as shown in Table 576. The PAD39INPEN and
PAD44INPEN bits must be set. PAD39PULL, PAD40PULL and PAD44PULL should be cleared.
A variety of pads may be used for up to four nCE signals to select up to four separate slaves. The nCE
signals are pre-muxed into a signal group called NCE. The muxing configuration is shown in Table 564.
The PADnINPEN and PADnPULL bits of any pad used for nCE should be cleared.
11.5.1.12IO Master 5 4-wire SPI Connection
Four-wire SPI mode of IO Master 5 uses pad 48 as SCK, pad 49 as MISO and pad 47 as MOSI. This mode
is configured by setting the PADnFNCSEL fields as shown in Table 577. The PAD48INPEN and
PAD47INPEN bits must be set. PAD48PULL, PAD49PULL and PAD47PULL should be cleared.
A variety of pads may be used for up to four nCE signals to select up to four separate slaves. The nCE
signals are pre-muxed into a signal group called NCE. The muxing configuration is shown in Table 564.
The PADnINPEN and PADnPULL bits of any pad used for nCE should be cleared.
11.5.1.13IO Master 0 3-wire SPI Connection
Three-wire SPI mode of IO Master 0 uses pad 5 as SCK and pad 6 as MOSI/MISO. This mode is
configured by setting the PADnFNCSEL fields as shown in Table 578. The PAD5INPEN and PAD6INPEN
bits must be set. PAD5PULL and PAD6PULL should be cleared. Pad 7 may be used for other functions.
Table 576: IO
Master 4 4-wire SPI Configuration
Field Value
PAD39FNCSEL 5
PAD40FNCSEL 5
PAD44FNCSEL 5
Table 577: IO Master 5 4-wire SPI Configuration
Field Value
PAD48FNCSEL 5
PAD49FNCSEL 5
PAD47FNCSEL 5
Table 578: IO Master 0 3-wire SPI Configuration
Field Value
PAD5FNCSEL 1
PAD6FNCSEL 0