AN2131SC Cypress Semiconductor Corp, AN2131SC Datasheet - Page 81

• Manufacturer Part Number: AN2131SC
• Description: IC MCU 8051 8K RAM 24MHZ 44QFP
• Manufacturer: Cypress Semiconductor Corp
• Series: EZ-USB®r

Specifications of AN2131SC

• Applications: USB Microcontroller
• Core Processor: 8051
• Program Memory Type: ROMless
• Controller Series: AN213x
• Ram Size: 8K x 8
• Interface: I²C, USB
• Number Of I /o: 16
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 44-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 428-1306; AN2131SC

These requests are always handled by the EZ-USB core (ReNum=0 or 1). This means that
0xA0 is reserved by the EZ-USB chip, and therefore should never be used for a vendor
request. Cypress Semiconductor also reserves bRequest values 0xA1 through 0xAF, so
your system should not use these bRequest values.
A host loader program typically writes 0x01 to the CPUCS register to put the 8051 into
RESET, loads all or part of the EZ-USB RAM with 8051 code, and finally reloads the
CPUCS register with 0 to take the 8051 out of RESET. The CPUCS register is the only
USB register that can be written using the Firmware Download command.
Firmware loads are restricted to internal EZ-USB memory.
Page 5-6
When ReNum=1 at Power-On
At power-on, the ReNum bit is normally set to zero so that the EZ-USB handles device
requests over CONTROL endpoint zero. This allows the core to download 8051 firm-
ware and then reconnect as the target device.
At power-on, the EZ-USB core checks the I
finds one, and the first byte of the EEPROM is 0xB2, the core copies the contents of the
EEPROM into internal RAM, sets the ReNum bit to 1, and un-RESETS the 8051. The
8051 wakes up ready-to-run firmware in RAM. The required data form at for this load
module is described in the next section.
Byte
0
1
2
3
4
5
6
7
bmRequest
bRequest
wValueL
wValueH
wIndexL
wIndexH
wLengthL
wLengthH
Field
Table 5-4. Firmware Upload
AddrH
AddrL
Value
Chapter 5. EZ-USB CPU
LenH
0xC0
0xA0
LenL
0x00
0x00
Vendor Request, IN
“Firmware Load”
Starting Address
Number of Bytes
2
C bus for the presence of an EEPROM. If it
Meaning
8051 Response
None required
EZ-USB TRM v1.9