LM3S2B93_16 Datasheet, PDF (519/1196 Pages) Texas Instruments – Stellaris LM3S2B93 Microcontroller

Stellaris^® LM3S2B93 Microcontroller
Bit/Field
17:16
15:8
7:6
5:4
3:2
Name
reserved
MAXWAIT
reserved
ASIZE
reserved
Type
RO
R/W
RO
R/W
RO
Reset
0x0
0x00
0x0
0x0
Description
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
Maximum Wait
This field defines the maximum number of EPI clocks to wait while the
iRDY signal (see RDYEN) is holding off a transaction. If this field is 0,
the transaction is held forever. If the maximum wait of 255 clocks
(MAXWAIT=0xFF) is exceeded, an error interrupt occurs and the
transaction is aborted/ignored.
Note:
When the MODE field is configured to be 0x0 and the BLKEN
bit is set in the EPICFG register, enabling General-Purpose
mode, this field defaults to 0xFF.
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
Address Bus Size
This field defines the size of the address bus. The address can be up
to 4-bits wide with a 24-bit data bus, up to 12-bits wide with a 16-bit data
bus, and up to 20-bits wide with an 8-bit data bus. If the full address bus
is not used, use the least significant address bits. Any unused address
bits can be used as GPIOs by clearing the AFSEL bit for the
corresponding GPIOs. Also, if RDYEN is 1, then the address sizes are
1 smaller (3, 11, 19).
The values are:
Value Description
0x0 No address
0x1 Up to 4 bits wide.
0x2 Up to 12 bits wide. This size cannot be used with 24-bit data.
0x3 Up to 20 bits wide. This size cannot be used with data sizes
other than 8.
0x0
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
July 03, 2014
519
Texas Instruments-Production Data