Arm® Corstone™ SSE
-300 with Cortex®-
M55 and Ethos™
-U55 :
Example Subsystem for MPS3 Application Note AN547
DAI 0547C
Issue C
8 Shield Support
Copyright
©
2020, 2021 Arm Limited (or its affiliates). All rights reserved.
Non-Confidential
Page 46 of 64
8
Shield Support
This SMM supports external shield devices. To enable the Shield support, two SPI, two UART and two I
2
C
interfaces are multiplexed with GPIO over the Shield Headers.
GPIO x3
UART x2
SPI x2
I2C x2
IO
M
U
X
V2M-MPS3
– HBI0309
FPGA Application Note
Shield0
Shield1
Figure 8-1 : Shield Device Expansion
Multiplexing is controlled by the alternative function output from the associated GPIO Register. An
experimental second alternative function is multiplexed for pins 1-9 of Shield 0 and these are controlled
through GPIOALT2 in the FPGAIO Registers at address offset 0x0C
.
The second ALT function is unused on AN547 and is not shown in the following table.
MPS3
GPIO
ALT Function 1
ALT Description 1
SH0_IO0
GPIO0_0
UART3 RXD
–
SH0_RXD
Shield 0 UART Receive
SH0_IO1
GPIO0_1
UART3 TXD
–
SH0_TXD
Shield 0 UART Transmit
SH0_IO2
GPIO0_2
-
-
SH0_IO3
GPIO0_3
-
-
SH0_IO4
GPIO0_4
-
-
SH0_IO5
GPIO0_5
-
-
SH0_IO6
GPIO0_6
-
-
SH0_IO7
GPIO0_7
-
-
SH0_IO8
GPIO0_8
-
-
SH0_IO9
GPIO0_9
-
-
SH0_IO10
GPIO0_10
SPI3 SS
–
SH0_nCS
Shield 0 SPI Chip Select