GR740-UM-DS, Nov 2017, Version 1.7
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GR740
1.11
Register descriptions
An example register, showing the register layout used throughout this document, can be seen
in table 3. The values used for the reset value fields are described in table 4, and the values
used for the field type fields are described in table 5. Fields that are named RESERVED,
RES, or R are read-only fields. These fields can be written with zero or with the value read
from the same register field.
Table 3.
<Address> - <Register acronym> - <Register name>
31
24 23
16 15
8
7
0
EF3
EF2
EF1
EF0
<Reset value for EF3>
<Reset value for EF2>
<Reset value for EF1>
<Reset value for EF0>
<Field type for EF3>
<Field type for EF2>
<Field type for EF1>
<Field type for EF0>
31: 24
Example field 3 (EF3) - <Field description>
23: 16
Example field 2 (EF2) - <Field description>
15: 8
Example field 1 (EF1) - <Field description>
7: 0
Example field 0 (EF0) - <Field description>
Table 4.
Reset value definitions
Value
Description
0
Reset value 0.
1
Reset value 1. Used for single-bit fields.
0xNN
Hexadecimal representation of reset value. Used for multi-bit fields.
0bNN
Binary representation of reset value. Used for multi-bit fields.
NR
Field not reset
*
Special reset condition, described in textual description of the field. Used for example when reset
value is taken from a pin.
-
Don’t care / Not applicable
Table 5.
Field type definitions
Value
Description
r
Read-only. Writes have no effect.
w
Write-only. Used for a writable field in a register where the field’s read-value has no meaning.
rw
Readable and writable.
rw*
Readable and writable. Special condition for write, described in textual description of field.
wc
Write-clear. Readable, and cleared when written with a 1
cas
Readable, and writable through compare-and-swap. Only applies to SpaceWire Plug-and-Play regis-
ters.