ST7260E1 STMicroelectronics, ST7260E1 Datasheet - Page 97

• Manufacturer Part Number: ST7260E1
• Description: LOW SPEED USB 8-BIT MCU FAMILY WITH UP TO 8K FLASH/ROM AND SERIAL COMMUNICATION INTERFACE (SCI)
• Manufacturer: STMicroelectronics

Specifications of ST7260E1

• 4 Or 8 Kbytes Program Memory: high density Flash (HDFlash), or FastROM with readout and write protection

ST7260xx
14.4.10
14.5
14.5.1
Table 45.
These bits are written by software. Hardware sets the STAT_RX bits to NAK when a correct
transfer has occurred (CTR=1) related to an OUT or SETUP transaction addressed to this
endpoint, so the software has the time to elaborate the received data before acknowledging
a new transaction.
Bits 3:0 = EA[3:0] Endpoint address.
Software must write in this field the 4-bit address used to identify the transactions directed to
this endpoint. Usually EP1RB contains “0001” and EP2RB contains “0010”.
Endpoint 0 register B (EP0RB)
This register is used for controlling data reception on Endpoint 0. It is also reset by the USB
bus reset.
Bit 7 = Forced by hardware to 1.
Bits 6:4 = Refer to the EPnRB register for a description of these bits.
Bits 3:0 = Forced by hardware to 0.
Programming considerations
The interaction between the USB interface and the application program is described below.
Apart from system reset, action is always initiated by the USB interface, driven by one of the
USB events associated with the Interrupt Status Register (ISTR) bits.
Initializing the registers
At system reset, the software must initialize all registers to enable the USB interface to
properly generate interrupts and DMA requests.
EP0RB
R/W
7
1
STAT_RX1
0
0
1
1
STAT_RX bits
DTOG
R/W
RX
6
STAT
RX1
R/W
5
STAT_RX0
0
1
0
1
STAT
RX0
R/W
4
DISABLED: reception transfers cannot be
executed.
STALL: the endpoint is stalled and all reception
requests result in a STALL handshake.
NAK: the endpoint is naked and all reception
requests result in a NAK handshake.
VALID: this endpoint is enabled for reception.
R/W
3
0
R/W
2
0
Reset value:
Meaning
USB interface (USB)
R/W
1
0
1000 0000 (80h)
R/W
0
0
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