4 external eeprom – Renesas CPU Board M3A-HS19 User Manual
Page 27
Features and Specifications
2.3.4 External EEPROM
Rev.1.01 Oct 28, .2008
2-11
REJ10J1351-0101
2
2.3.4 External EEPROM
The M3A-HS19 is provided with an EEPROM for storing MAC address.
Access to the EEPROM is enabled by using the SH7261 I/O ports (PC03, PC02, PC01 and PC00). A MAC address
consists of 48-bit numbers.
Table 2.3.6 lists instruction sets, and Figure 2.3.6 shows the block diagram of CPU and EEPROM connection.
Figure 2.3.7 shows the EEPROM-AC timing and Figure 2.3.8 shows EEPROM-read/write timing.
Settings for following instruction sets are not required;
-
A7 to A0 for WRAL, ERAL, EWEN, and EWDS instructions
-
Data for ERASE, ERAL, EWEN and EWDS instructions
Table 2.3.6 Instruction Sets (S-93C76AFT)
Start Bit
Operation
Code
Address
Data
Command
SK
1
2
3
4
5
6~13
14~29
READ
1
1
0
-
A8
A7~A0
D15~D0 (OUT)
WRITE
1
0
1
-
A8
A7~A0
D15~D0 (IN)
ERASE
1
1
1
-
A8
A7~A0
-
WRAL
1
0
0
0
1
-
D15~D0(IN)
ERAL
1
0
0
1
0
-
-
EWEN
1
0
0
1
1
-
-
EWDS
1
0
0
0
0
-
-
Figure 2.3.6 CPU and EEPROM Connection
S-93C76AFT(U4)
PC03/MII_RXD3
SH7619 (U1)
SK
PC02/MII_RXD2
PC01/MII_RXD1
PC00/MII_RXD0
EEPROM
CS
DI
DO
GND
NC
TEST
Vcc
3.3 V