DS80C410 Datasheet, PDF (50/102 Pages) Dallas Semiconductor – Network Microcontrollers with Ethernet and CAN

DS80C410/DS80C411 Network Microcontrollers with Ethernet and CAN
Table 9. Data Memory Cycle Stretch Values
MD2 MD1 MD0
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
STRETCH
VALUE
0 (Note 1)
1 (Note 2)
2
3
4
5
6
7
MOVX
MACHINE
CYCLES
2
3
4
5
9
10
11
12
APPROXIMATE RD, WR PULSE WIDTH
(IN OSCILLATOR CLOCKS)
(4X/2X = 1
(4X/2X = 0
(4X/2X = X
(4X/2X = X
CD1:0 = 00) CD1:0 = 00) CD1:0 = 10) CD1:0 = 11)
0.5 tCLK
1 tCLK
1 tCLK
2 tCLK
2 tCLK
4 tCLK
512 tCLK
1024 tCLK
2 tCLK
3 tCLK
4 tCLK
6 tCLK
8 tCLK
12 tCLK
2048 tCLK
3072 tCLK
4 tCLK
5 tCLK
8 tCLK
10 tCLK
16 tCLK
20 tCLK
4096 tCLK
5120 tCLK
6 tCLK
7 tCLK
12 tCLK
14 tCLK
24 tCLK
28 tCLK
6144 tCLK
7168 tCLK
Note 1: All internal MOVX operations execute at the 0 stretch setting.
Note 2: Default stretch setting for external MOVX operations following reset, prior to execution of internal ROM.
Internal MOVX SRAM
The DS80C410/411 incorporates 73.25kBytes on-chip SRAM for MOVX memory. The on-chip SRAM is physically
divided into four memory blocks: a dedicated 64Kx8 data or program/data memory, a 1Kx8 memory block for
extended stack or data memory, and 256 bytes of dual port RAM for control and storage of CAN messages. The
address locations of these four blocks are fixed and cannot be altered. Figure 2 shows the default memory
configuration of the DS80C410.
Figure 2. Internal Data Memory
INTERNAL DATA MEMORY
FFFFFF
FFE000
FFDFFF
FFDC00
FFDBFF
2Kx32 SRAM
(DATA MEMORY OR
NETWORK BUFFER
MEMORY)
1Kx8 SRAM
(DATA MEMORY OR
OPTIONAL STACK)
256x8 DPSRAM
(CAN DATA MEMORY)
FFDB00
00FFFF
000000
64Kx8 SRAM
(DATA MEMORY)
The 8kB (2kx32) block is used by the Ethernet MAC as frame-buffer memory for incoming or outgoing packet data
and can, at the same time, be accessed by the DS80C410 as MOVX data memory. While the MAC is in use,
special care should be taken by user software to prevent undesirable MOVX writes from corrupting frame-buffer
memory. Note: that when the SA bit (ACON.2) is set, 1kB of the MOVX data memory is accessed by the 10-bit
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