XR21V1414 Datasheet, PDF (14/26 Pages) Exar Corporation – 4-CH FULL-SPEED USB UART

XR21V1414
4-CH FULL-SPEED USB UART
TABLE 3: SUPPORTED USB CONTROL COMMANDS
REV. 1.0.0
NAME
REQUEST
TYPE
REQUEST
VALUE
INDEX
LENGTH
DESCRIPTION
CDC_ACM_IF
SEND_BREAK
0x21
35
val val 0, 2, 0
0
0 Send a break for the speci-
LSB MSB ^{4, 6}
fied duration
XR_SET_REG
0x40
0
val 0 regis- block 0 0 Exar custom command: set
ter
one 8-bit register
val: 8-bit register value
register address: see
Table 6 on page 16
block number: see Table 4
on page 14
XR_GETN_REG
0xC0
1
0 0 regis- block count count Exar custom register: get
ter
LSB MSB
count 8-bit registers
register address: see
Table 6 on page 16
block number: see Table 4
on page 14
2.1 UART Block Numbers
The table below lists the block numbers for accessing each of the UART channels and the UART Manager..
TABLE 4: CONTROL BLOCKS
BLOCK NAME
BLOCK NUMBER
DESCRIPTION
UART Channel A
0
The configuration and control registers for UART channel A.
UART Channel B
1
The configuration and control registers for UART channel B.
UART Channel C
2
The configuration and control registers for UART channel C.
UART Channel D
3
The configuration and control registers for UART channel D.
UART Manager
4
The control registers for the UART Manager. The UART Manager
enables/disables the TX and RX FIFOs for each UART.
14