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GR716-DS-UM, May 2019, Version 1.29
384
www.cobham.com/gaisler
GR716
38
I
2
C master
The LEON3FT microcontroller comprises two separate I
2
C master (I2CMST) units. Each I
2
C master
unit controls its own external pins and has a unique AMBA address described in chapter 2.11.
The I
2
C master units are located on the APB bus in the address range from 0x8030E000 to
0x8030FFFF. See I
2
C master units connections in the next drawing. The figure shows memory loca-
tions and functions used for I
2
C master configuration and control.
The primary clock gating unit
GRCLKGATE
described in section 26 is used to enable/disable indi-
vidual I
2
C master units. The unit
GRCLKGATE
can also be used to perform reset of individual I
2
C
master units. Software must enable clock and release reset described in section 26 before I
2
C master
configuration and transmission can start.
External IO selection per I
2
C master unit is made in the system IO configuration register (
GRG-
PREG
) in the address range from 0x8000D000 to 0x8000D03F. See section 7.1 for further informa-
tion.
Each
I2CMSTx
unit controls its own external pins and has a unique AMBA address described in
chapter 2.11. I2CMST unit 0 and 1 have identical configuration and status registers. Configuration
and status registers are described in section 38.3.
The system can be configured to protect and restrict access to individual I
2
C-master unit in the
MEM-
PROT
unit. See section 47 for more information.
38.1
Overview
The I
2
C-master core is a modified version of the OpenCores I
2
C-Master with an AMBA APB inter-
face. The core is compatible with Philips I
2
C standard and supports 7- and 10-bit addressing. Stan-
Figure 59.
GR716
I
2
C-master
bus and pin connection
GPIO0
LEON3FT
Processor
Bridge
Bridge
MEMPROT
Bridge
APB
(0x80000000-
GRCLKGATE
0x800FFFFF)
APB
(0x80100000-
0x801FFFFF)
APB
(0x80300000-
0x803FFFFF)
I2CMST0
I2CMST1
IOMUX
GPIO63
Main AHB
(0x00000000-
0xFFFFFFFF)
Select Outputs
Enable I2Cx clocks
(0x8000D000 -
0x8000D03F)
(0x80006000 -
0x8000600F)
GRGPREG
Memory Protection
(0x8001A000 -
0x8001AFFF)