AN2131QC Cypress Semiconductor Corp, AN2131QC Datasheet - Page 116

• Manufacturer Part Number: AN2131QC
• Description: IC MCU 8051 8K RAM 24MHZ 80BQFP
• Manufacturer: Cypress Semiconductor Corp
• Series: EZ-USB®r

Specifications of AN2131QC

• 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: 24
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 80-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 428-1307

4.
The main program loop tests the “got_EP2_data” flag, waiting until it is set by the end-
point 2 OUT interrupt service routine in Figure 6-10. This indicates that a new data
packet has arrived in OUT2BUF. Then the service routine is entered, where the flag is
cleared in line 2. The number of bytes received in OUT2BUF is retrieved from the
OUT2BC register (Endpoint 2 Byte Count) and saved in registers R6 and R7 in lines 7-10.
The dual data pointers are initialized to the source (OUT2BUF) and destination (IN2BUF)
buffers for the data transfer in lines 15-18. These labels represent the start of the 64-byte
buffers for endpoint 2-OUT and endpoint 2-IN, respectively. Each byte is read from the
OUT2BUF buffer and written to the IN2BUF buffer in lines 19-25. The saved value of
EZ-USB TRM v1.9
1
2
3
4
5
6
7
8
9
10
11 ;
12 ; Transfer the bytes received on the OUT2 endpoint to the IN2 endpoint
13 ; buffer.
14 ;
15
16
17
18
19 transfer:
20
21
22
23
24
25
26 ;
27 ; Load the byte count into IN2BC.
28 ;
29
30
31
32 ;
33 ; Load any byte count into OUT2BC.
34 ;
35
36
37
loop:
;
; The user sent bytes to OUT2 endpoint using the USB Control Panel.
; Find out how many bytes were sent.
;
Write the endpoint 2 transfer program.
Figure 6-10. Background Program Transfers Endpoint 2-OUT Data to Endpoint 2-IN
Number of bytes in r6 and r7.
jnb
clr
mov
movx
mov
mov
mov
inc
mov
inc
movx
inc
inc
movx
inc
inc
djnz
mov
mov
movx
mov
movx
sjmp
got_EP2_data,loop
got_EP2_data
dptr,#OUT2BC
a,@dptr
r7,a
r6,a
dptr,#OUT2BUF
dps
dptr,#IN2BUF
dps
movx
dptr
dps
@dptr,a
dptr
dps
r7,transfer
dptr,#IN2BC
a,r6
@dptr,a
dptr,#OUT2BC
@dptr,a
loop
Chapter 6. EZ-USB CPU
This arms in IN transfer
This arms the next OUT transfer.
; clear my flag
; point to OUT2 byte count register
; get the value
; stash the byte count
; save here also
; first data pointer points to EP2OUT buffer
; select the second data pointer
; second data pointer points to EP2IN buffer
; back to first data pointer
get OUT byte
; bump the pointer
; second data pointer
; put into IN buffer
; bump the pointer
; first data pointer
; get other saved copy of byte count
; this arms the IN transfer
; use whatever is in acc
; start checking for another OUT2 packet
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