Extended Config
W/R
Addr.: 0x7000_0020 Default: 0x0303_0000
Description
Setting of additional functionalities
Bit No.
Name
Description
31 Reserved
Reserved
30
TEST_1
Test Mode 1
0: 200 µs delay after system reset (SDRAM power-up)
1: Delay after system reset is immediately terminated
29
TEST_2
Test Mode 2
0: Normal function
1: All SDRAM accesses are misses
28..26 Reserved
Reserved
25
ADB
Active data bus
After each access to the SDRAM, the data bus is driven actively to 1 in order
to support integrated pull-ups.
24
ASDB
Asynchronous active data bus
After each access to the asynchronous area, the data bus is driven actively
to 1 at the end of the Hold phase in order to support integrated pull-ups.
23..20 Reserved
Reserved
19
TEST_3
Test Mode 3
0: Normal function
1: DTR_N = Test Output
18 Reserved
Reserved
17..16
BURST_LENGTH
SDRAM burst length
00: 1
01: 2
10: Full Page, Read INCR_S burst length = 4
11: Full Page, Read INCR_S burst length = 8
15 Reserved
Reserved
14
TRCD/TCD
Time between the SDRAM commands
Activate and read/write, precharge and activate
0: 1 AHB clock cycles
1: 2 AHB clock cycle
13..9 Reserved
Reserved
8
SDSIZE
SDRAM bank size
0: 32-bit data bus
1: 16-bit data bus
7
ATIRQ
0: Timeout watchdog for asynchronous accesses disabled
1: Timeout watchdog for asynchronous accesses enabled
After the watchdog expires (256 AHB clock cycles), an interrupt is triggered.
Setting Bit 7 to 0 deletes interrupt source.
6..0 Reserved
Reserved
Programming specification for EMIR registers:
For a correct setting of the SDRAM, the values for Burst_Length and SDRAM bank width must match up in the Extended
Config register. The bits must be set before the
MODE-Register-SET
command is initiated; otherwise, they are not
transferred to the SDRAM. The Mode-Register-Set command is initiated by writing to the bits [15:8] of the
SDRAM-
Bank-Config
register when bit 29 = 1 in the
SDRAM Refresh Control
register.
SDRAM 32-bit data width:
Extended Config[8] = 0
Extended Config[17:16] = 11
Full Page, Read INCR_S Burst Length = 8
Extended Config[17:16] = 10
Full Page, Read INCR_S Burst Length = 4
Extended Config[17:16] = 00
Burst Length = 1
SDRAM 16-bit data width:
Extended Config[8] = 1
Extended Config[17:16] = 11
Full Page, Read INCR_S Burst Length = 8
Extended Config[17:16] = 10
Full Page, Read INCR_S Burst Length = 4
Extended Config[17:16] = 01
Burst Length = 2
All other settings cause malfunctions
The
Mode Register Set
command is initiated by writing to the bit in the register SDRAM_Bank_Config[15:8]. (Register
SDRAM_Refresh-Control[29] =1)
Copyright © Siemens AG 2007. All rights reserved.
73
ERTEC 200 Manual
Technical data subject to change
Version 1.1.0