TC1796
System Units (Vol. 1 of 2)
LMB External Bus Unit
User’s Manual
13-105
V2.0, 2007-07
EBU, V2.0
BCGEN
[21:20] rw
Byte Control Signal Control
This bit field selects the timing mode of the byte
control signals.
00
B
Byte control signals follow chip select timing.
01
B
Byte control signals follow control signal timing
(RD, RD/WR) (default after reset).
10
B
Byte control signals follow write enable signal
timing (RD/WR only).
11
B
Reserved.
PORTW
[23:22] rw
Port Width
00
B
Reserved.
01
B
16-bit.
10
B
32-bit (default after reset).
11
B
Reserved.
WAIT
[25:24] rw
External Wait State Control
This bit determines the function of the WAIT input.
This is specific to the device type (i.e. the AGEN
field).
00
B
OFF (default after reset).
01
B
Asynchronous input at WAIT (default after
reset).
10
B
Synchronous input at WAIT.
11
B
Data Handshake input at WAIT (Burst Flash
devices only).
0
[27:26] rw
Reserved
Read as 0 after reset; must be always written with 0.
AGEN
[30:28] rw
Address Generation Control
This bit field selects the access type for the emulator
chip select region.
000
B
Demultiplexed (asynch.) access selected
(default after reset).
010
B
Burst Flash access selected.
Other values of AGEN are reserved and must not be
used!
WRITE
31
rw
Memory Region Write Protection
0
B
Writes to the memory region are enabled
(default after reset).
1
B
Writes to the memory region are disabled.
Field
Bits
Type Description