M30240ECFP MITSUBISHI [Mitsubishi Electric Semiconductor], M30240ECFP Datasheet - Page 55

• Manufacturer Part Number: M30240ECFP
• Description: M30240 Group Specification
• Manufacturer: MITSUBISHI [Mitsubishi Electric Semiconductor]

Preliminary Specifications REV. E
Specifications in this manual are tentative and subject to change
Universal Serial Bus
Figure 1.38: USB Frame Number Low Register
Figure 1.39: USB Frame Number High Register
Figure 1.40:
2.18.4.8 USB Frame Number Registers
2.18.4.9 USB ISO Control Register
The USB Frame Number Low Register, shown in Figure 1.38, contains the lower 8 bits of the 11-bit frame
number received from the host. The USB Frame Number High Register, shown in Figure 1.39 contains the
upper 3 bits of the 11-bit frame number received from the host.
The USB ISO Control Register, shown in Figure 1.40, contains two global bits, ISO_UPD and AUTO_FL for
controlling endpoints 1-4 isochronous data transfer.
When ISO_UPD = “0”, a data packet in an endpoint’s IN FIFO is always ‘ready to transmit’ upon receiving the
next IN_TOKEN from the host (with matched address and endpoint number) if the endpoint’s IN_PKT_RDY
is set.
When ISO_UPD = “1” and the ISO/TOGGLE_INIT bit of the corresponding endpoint’s IN CSR is set, the in-
ternal ‘ready to transmit’ signal to the transmit control logic is not activated when the endpoint’s IN_PKT_RDY
is set. Instead, it is activated when the next SOF is received, this way, the data loaded in frame n is transmitted
out in frame n+1. The ISO_UPD bit is a global bit for endpoints 1-4 and works with isochronous pipes only.
When AUTO_FL = “1”, ISO_UPD = “1”, a particular IN endpoint’s ISO/TOGGLE_INIT bit is set, and the IN
endpoint’s IN_PKT_RDY = “1”, the USB FCU detects a SOF packet and the USB FCU automatically flushes
the oldest packet from the IN FIFO. In this case, IN_PKT_RDY = “1”, indicates that two data packets are in
the IN FIFO. Because double buffering is a requirement for ISO transfer, MAXP must be set to less than or
equal to 1/2 of the FIFO size.
USB Frame Number Low Register
b7
USB Frame Number High Register
b7
USB ISO Control Register
0 0 0 0
b6
USB ISO Control Register
b7
b6
b5
b6
b5
b4
b5
b4
0 0 0 0 0 0
b3
b4
b3
0
b2
b3
b2
b1
b2
b1
b0
b1
b0
FN0 to FN7
b0
Bit symbol
FN8
FN9
FN10
Reserved
Bit symbol
Bit symbol
Reserved
AUTO_FL
ISO_UPD
Symbol
USBSOFL
Symbol
USBSOFH
Symbol
USBISOC
Lower 8 bits of the 11-bit
frame number issued with a
SOF token
Upper 3 bits of the 11-bit
frame number issued with a
SOF token
AUTO_FLUSH Bit
ISO_UPDATE Bit
Bit name
1-55
Bit name
Bit name
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
0 : Hardware auto FIFO flush diabled
1 : Hardware auto FIFO flush enabled
0 : ISO_UPDATE disabled
1 : ISO_UPDATE enabled
Address
0306
Must always be set to "0"
Address
0307
Address
0308
16
16
16
Must always be set to "0"
Function
Function
Function
When reset
When reset
When reset
Mitsubishi microcomputers
00
00
00
16
M30240 Group
16
16
R
R
R
W
X
W
W
X
X