User Manual

Apollo3 Blue Datasheet
DS-A3-0p9p1 Page 392 of 909 2019 Ambiq Micro, Inc.
All rights reserved.
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.
11.5.1.8 IO Master 1 4-wire SPI Connection
Four-wire SPI mode of IO Master 1 uses pad 8 as SCK, pad 9 as MISO and pad 10 as MOSI. This mode is
configured by setting the PADnFNCSEL fields as shown in Table 573. The PAD8INPEN and PAD9INPEN
bits must be set. PAD8PULL, PAD9PULL and PAD10PULL 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.
11.5.1.9 IO Master 2 4-wire SPI Connection
Four-wire SPI mode of IO Master 2 uses pad 27 as SCK, pad 28 as MOSI and pad 25 as MISO. This mode
is configured by setting the PADnFNCSEL fields as shown in Table 574. The PAD27INPEN and
PAD28INPEN bits must be set. PAD27PULL, PAD28PULL and PAD25PULL 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.
11.5.1.10IO Master 3 4-wire SPI Connection
Four-wire SPI mode of IO Master 3 uses pad 42 as SCK, pad 43 as MISO and pad 38 as MOSI. This mode
is configured by setting the PADnFNCSEL fields as shown in Table 575. The PAD42INPEN and
PAD38INPEN bits must be set. PAD38PULL, PAD42PULL and PAD43PULL should be cleared.
Table 573: IO
Master 1 4-wire SPI Configuration
Field Value
PAD8FNCSEL 1
PAD9FNCSEL 1
PAD10FNCSEL 1
Table 574: IO Master 2 4-wire SPI Configuration
Field Value
PAD27FNCSEL 5
PAD28FNCSEL 5
PAD25FNCSEL 5
Table 575: IO Master 3 4-wire SPI Configuration
Field Value
PAD38FNCSEL 5
PAD42FNCSEL 5
PAD43FNCSEL 5