cs5954am Cypress Semiconductor Corporation., cs5954am Datasheet - Page 17

• Manufacturer Part Number: cs5954am
• Description: Usb Controller For Nand Flash
• Manufacturer: Cypress Semiconductor Corporation.

Table 4-4. Software Interrupt Table (continued)
All these vector interrupts are Read/Write accessible. User can overwrite these default software interrupt vectors by replacing
the user’s interrupt service subroutine.
4.12
The CS5954AM provides an interface to an external serial EEPROM. The interface is implemented using General-purpose I/O
signals. A variety of serial EEPROM formats can be supported: currently the BIOS ROM supports the two-wire serial EEPROM
type. The serial EEPROM can be used to store specific peripheral USB configuration and add on value functions. It can also be
used for field product upgrades
The CS5954 BIOS uses an interrupt to read and write to/from an external serial EEPROM. The recommended serial EEPROM
device is a 2-wire serial CMOS EEPROM (AT24CXX device family). Currently, the CS5954AM BIOS Revision 1.1 allows reading/
writing to/from EEPROM, up to 2K Bytes (16K bits), 2-wire serial interface device (i.e., AT24C16).
The user’s program and USB vendor/device configuration can be programmed and stored into the external EEPROM device. On
power-up the content of the EEPROM will be downloaded into RAM and may be executed as code or used as data, or both. The
advantage of the 2-wire serial interface/EEPROM interface is the space and cost saving when compared to using an external
eight-bit PROM/EPROM.
The CS5954AM BIOS uses two GPIO pins, GPIO31 and GPIO30 to interface to an external serial EEPROM (see Figure 4-3):
Document #: 38-08025 Rev. **
• GPIO31 is connected to the Serial Clock Input (SCL).
• GPIO30 is connected to the Serial Data (SDA).
• We recommend you add a 5K to 15K pull-up resistor on the Data line (e.g., GPIO30).
• Pin 1 (A0), Pin 2 (A1), Pin 3 (A2), Pin 4 (GND) and Pin 7 Write Protect) are connected to Ground.
Interrupt Number
105 (0x69)
91 (0x5b)
93 (0x5d)
94 (0x5e)
96 (0x60)
92 (0x5c)
95 (0x5f)
106–109
110–124
125–127
97–104
Serial EEPROM Interface (2-wire serial interface)
Vector Address
0xD4–0xDA
0xC2–0xD0
0xDE–0xF8
0xFA–0xFE
0x00BA
0x00BC
0x00BE
0x00C0
0x00D2
0x00B6
0x00B8
Figure 4-3. 2-Wire Serial Interface 2K-byte Connection
Figure 4-4. 2-Wire Serial Interface 16K Connection
Data: configuration desc. Default = Cypress configuration
Data: string descriptor. Default = Cypress string desc.
USB_PARSE_CONFIG_INT
USB_LOADER_INT
USB_DELTA_CONFIG_INT
USB_PULLUP_INT
Reserved for future addition secondary USB port
POWER_DOWN_SUBROUTINE
Reserved for future secondary USB Port
User’s ISR or internal peripheral interrupt
Reserved for the debugger
1
2
3
4
1
2
3
4
EEPROM
EEPROM
A0
A1
A2
GND
A0
A1
A2
GND
AT24C16
AT24C128
ADVANCE
INFORMATION
VCC
VCC
SDA
SDA
SCL
SCL
WP
WP
8
7
6
5
8
7
6
5
GPIO31
GPIO30
GPIO30
GPIO31
5K
5K
Interrupt Type
VCC
VCC
0.1uF
0.1uF
[6]
[6]
CS5954AM
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