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GR716-DS-UM, May 2019, Version 1.29
140
www.cobham.com/gaisler
GR716
18
UART Serial Interface
The GR716 comprises 6 separate UART units and 2 debug and remote access UART units. The 2
debug and remote access UART units also called AHBUART units are described in section 48. This
chapter only describes the UART units also called APBUART. The main difference between the
UART units described in this section and the debug UART units are the debug and remote access
UART units capability to respond to external UART singling without software support. The two
debug and remote access UART units can also act as a master on the internal bus without software
support. The UART units described in this section requires software support for all operations.
The APB UART units are located on APB bus in the address range from 0x80300000 to 0x80305FFF.
See UART units connections in the next drawing. The figure shows memory locations and functions
used for UART configuration and control.
The primary clock gating unit
GRCLKGATE
described in section 26 is used to enable/disable indi-
vidual UART units. The unit
GRCLKGATE
can also be used to perform reset of individual UART
units. Software must enable clock and release reset described in section 26 before UART configura-
tion and transmission can start.
External IO selection per UART unit is made in the system IO configuration register (
GRGPREG
) in
the address range from 0x8000D000 to 0x8000D03F. See section 7.1 for further information.
Each
UARTx
unit controls its own external pins and has a unique AMBA address described in chap-
ter 2.11. UART unit 0, 1, 2, 3, 4 and 5 have identical configuration and status registers. Configuration
and status registers are described in section 18.7.
The system can be configured to protect and restrict access to individual UART unit in the
MEM-
PROT
unit. See section 47 for more information.
Figure 12.
GR716 UART bus and pin connection
GPIO0
LEON3FT
Processor
Bridge
Bridge
MEMPROT
Bridge
APB
(0x80000000-
GRCLKGATE
0x800FFFFF)
APB
(0x80100000-
0x801FFFFF)
APB
(0x80300000-
0x803FFFFF)
UART0
UART1
UART2
UART3
UART4
UART5
IOMUX
GPIO63
Main AHB
(0x00000000-
0xFFFFFFFF)
Select Outputs
Enable UARTx clocks
(0x8000D000 -
0x8000D03F)
(0x80006000 -
0x8000600F)
GRGPREG
Memory Protection
(0x8001A000 -
0x8001AFFF)