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GR716-DS-UM, May 2019, Version 1.29
445
www.cobham.com/gaisler
GR716
45
SPI for Space Slave Controller
The GR716 microcontroller comprises an SPI for Space Slave controller (SPI4S). The SPI for Space
Slave controller controls its own external pins and has a unique AMBA address described in chapter
2.11. The nominal SPI for Space Slave interface is connected via LVDS transceivers to external pins
and the redundant interface is connected to external pins via the IOMUX.
The control and status register are located on APB bus in the address range from 0x8040E000 to
0x8040EFFF. See SPI for Space Slave controller connections in the next drawing. The figure shows
memory locations and functions used for SPI4S configuration and control.
The primary clock gating unit
GRCLKGATE
described in section 26 is used to enable/disable the
SPI for Space Slave controller. The unit
GRCLKGATE
can also be used to perform reset of the SPI
for Space Slave controller. Software must enable clock and release reset described in section 26
before configuration and transmission can start.
External IO selection and configuration is made in the system IO and LVDS configuration registers
(
GRGPREG
) in the address range from 0x8000D000 to 0x8000D03F and 0x80007030. See section
7.1 for further information.
The system can be configured to protect and restrict access to the SPI for Space Slave controller in the
MEMPROT
unit. See section 47 for more information.
45.1
Overview
This core is a Dual Port SPI Slave device that provides link between SPI and AMBA AHB and APB
ports. Core features include configurable word length (4, 5, 6 ... 32 bits), bit ordering and all four SPI
modes are supported. This core also has redundant SPI ports which can be interfaced using two differ-
ent masters. The slave takes two sets of SPI interfaces (nominal and redundant each consists of two
data signals, one clock signal and one chip select signal).
Figure 75.
GR716 SPI4S bus and pin connection
GPIO0
LEON3FT
Processor
APB
(0x80000000-
0x800FFFFF)
IOMUX
GPIO63
Main AHB
(0x00000000-
0xFFFFFFFF)
Select Outputs
Enable SPI4S clock
(0x8000D000 -
0x8000D03F)
(0x80006000 -
0x8000600F)
GRGPREG
Select LVDS
(0x80007030)
LVDSMUX
MEMPROT
Memory Protection
(0x8001A000 -
0x8001AFFF)
Bridge
TX0
RX2
Bridge
GRCLKGATE
Bridge
DMA
AHB
Bridge
IMEM
128K
DMEM
64K
AM
BA
SPI4S