ST72T774J9B1 STMicroelectronics, ST72T774J9B1 Datasheet - Page 84

• Manufacturer Part Number: ST72T774J9B1
• Manufacturer: STMicroelectronics

Specifications of ST72T774J9B1

• Cpu Family: ST7
• Device Core Size: 8b
• Frequency (max): 24MHz
• Interface Type: I2C/USB
• Program Memory Type: EPROM
• Program Memory Size: 60KB
• Total Internal Ram Size: 1KB
• # I/os (max): 31
• Number Of Timers - General Purpose: 1
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 4V
• On-chip Adc: 1-chx8-bit
• On-chip Dac: 1-chx8-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Pin Count: 42
• Package Type: SPDIP
• Lead Free Status / Rohs Status: Specific Sites Compliant

ST72774/ST727754/ST72734
USB INTERFACE (Cont’d)
ENDPOINT n REGISTER B (EPnRB)
Read / Write
Reset Value: 0000 xxxx (0xh)
These registers (EP1RB and EP2RB) are used for
controlling data reception on Endpoints 1 and 2.
They are also reset by the USB bus reset.
Note: Endpoint 2 and the EP2RB register are not availa-
Bit 7 = CTRL Control.
This bit should be 0.
Note: If this bit is 1, the Endpoint is a control endpoint.
Bit 6 = DTOG_RX Data toggle, for reception
transfers .
It contains the expected value of the toggle bit
(0=DATA0, 1=DATA1) for the next data packet.
This bit is cleared by hardware in the first stage
(Setup Stage) of a control transfer (SETUP
transactions start always with DATA0 PID). The
receiver toggles DTOG_RX only if it receives a
correct data packet and the packet’s data PID
matches the receiver sequence bit.
Bit 5:4 = STAT_RX [1:0] Status bits, for reception
transfers.
These bits contain the information about the
endpoint status, which are listed in the following
table:
84/144
CTRL
7
ble on some devices (see device feature list and
register map).
(Endpoint 0 is always a control Endpoint, but it is
possible to have more than one control Endpoint).
DTOG
_RX
STAT
_RX1
STAT
_RX0
EA3
EA2
EA1
EA0
0
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)
Read / Write
Reset Value: 1000 0000 (80h)
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.
Bit 6:4 = Refer to the EPnRB register for a
description of these bits.
Bit 3:0 = Forced by hardware to 0.
STAT_RX1 STAT_RX0 Meaning
0
0
1
1
7
1
DTOG
RX
0
1
0
1
STAT
RX1
STAT
RX0
DISABLED: reception
transfers
executed.
STALL: the endpoint is
stalled and all reception
requests result in a STALL
handshake.
NAK: the endpoint is na-
ked and all reception re-
quests result in a NAK
handshake.
VALID: this endpoint is
enabled for reception.
0
0
cannot
0
0
0
be