External Eeprom - Renesas CPU Board M3A-HS19 User Manual

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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
Command
READ
WRITE
ERASE
WRAL
ERAL
EWEN
EWDS
Rev.1.01 Oct 28, .2008
REJ10J1351-0101
Table 2.3.6 Instruction Sets (S-93C76AFT)
Start Bit
SK
1
1
1
1
1
1
1
1
SH7619 (U1)
PC03/MII_RXD3
PC02/MII_RXD2
PC01/MII_RXD1
PC00/MII_RXD0
Figure 2.3.6 CPU and EEPROM Connection
Operation Address
Code
2 3 4 5
1 0 - A8 A7~A0
0 1 - A8 A7~A0
1 1 - A8 A7~A0
0 0 0 1
0 0 1 0
0 0 1 1
0 0 0 0
EEPROM
S-93C76AFT(U4)
CS
SK
DI
DO
Features and Specifications
2.3.4 External EEPROM
Data
6~13 14~29
D15~D0 (OUT)
D15~D0 (IN)
-
- D15~D0(IN)
- -
- -
- -
3.3 V
Vcc
TEST
NC
GND
2-11