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GR716-DS-UM, May 2019, Version 1.29
465
www.cobham.com/gaisler
GR716
46.3.1
Table 624.
0x00 - CONF - Configuration register
Configuration Register
46.3.2
Table 625.
0x04 - CTRL - Control register
Control Register
46.3.3 Status Register
31
12
11
10
9
8
7
0
RESERVED
DUMMYBYTES
ADDRBYTES
READCMD
0
0x0
0x0
0x3
r
rw
rw
rw
31 :12
RESERVED
11:10
Use Dummy Byte (DUMMYBYTES) - Insert dummy bytes after last address bytes for higher speed
rates i.e. when read instruction bit is set to use FAST read mode. The bit field DUMMYBYTES is
the number of dummy bytes that is inserted after the last address byte.
9:8
Reduce number of address bytes (ADDRBYTES) - Default number of address bytes is set to 3.
"00"
Use 3 address bytes (Default)
"01"
Use 2 address bytes
"10"
Use 1 address byte
"11"
Use 3 address bytes. Bit field ADDRBYTES will automatically reset back to "00".
7:0
Read instruction (READCMD) - Read instruction that the core will use for reading from the memory
device.
31
5
4
3
2
1
0
RESERVED
RST
CSN
EAS
IEN
USRC
0
1
0
0
0
rw
rw
rw
rw
rw
31 :5
RESERVED
4
Reset core (RST) - By writing ‘1’ to this bit the user can reset the core. This bit is automatically
cleared when the core has been reset. Reset core should be used with care. Writing this bit has the
same effect as system reset. Any ongoing transactions, both on AMBA and to the SPI device will be
aborted.
3
Chip select (CSN) - Controls core chip select signal. This field always shows the level of the core’s
internal chip select signal. This bit is always automatically set to ‘1’ when leaving User mode by
writing USRC to ‘0’.
2
Enable Alternate Scaler (EAS) - When this bit is set the SPI clock is divided by using the alternate
scaler. Set scaler to system clock frequency divided by 4. Default scaler is system clock divided by
16.
1
Interrupt Enable (IEN) - When this bit is set the core will generate an interrupt when a User mode
transfer completes.
0
User control (USRC) - When this bit is set to ‘1’ the core will accept SPI data via the transmit regis-
ter. Accesses to the memory mapped device area will return AMBA ERROR responses.
Table 626.
0x08 - STAT - Status register
31
3
2
1
0
RESERVED
INIT
BUSY
DONE
0
0
0
0
r
r
r
wc
31:3
RESERVED
2
Initialized (INIT) - This read only bit is set to ‘1’ when the SPI memory device has been initialized.
Accesses to the ROM area should only be performed when this bit is set to ‘1’.
1
Core busy (BUSY) - This bit is set to ‘1’ when the core is performing an SPI operation.