cx20493-35/app Conexant Systems, Inc., cx20493-35/app Datasheet - Page 42

• Manufacturer Part Number: cx20493-35/app
• Description: With Cx20493 Smartdaa?
• Manufacturer: Conexant Systems, Inc.

Table 3-2. CX81801 Modem Pin Signal Definitions for Parallel Interface (PARIF = High) (Continued)
3-10
HCS# (PD4)
HWT# (PD5)
HRD# (PD6)
HINT (PB7)
HA0-HA2
(PD0-PD2)
HD0-HD7
(PC0-PC7)
CX81801-7x/8x SmartV.XX Modem in 128-Pin LQFP with CX20493 in 32-Pin LQFP Data Sheet
Label
11
12
13
109
6-8
122-123, 125-
127, 1, 3-4
Pin
I
I
I
O
I
I/O
I/O
It
Ithpu
Ithpu
It/Ot8
Ithpd/Ot2
Ith/Ot8
I/O Type
Parallel Host Interface
Conexant
Host Bus Chip Select. HCS# input low enables the MCU host
bus interface.
Host Bus Write. HWT# is an active low, write control input. When
HCS# is low, HWT# low allows the host to write data or control
words into a selected MCU register.
Host Bus Read. HRD# is an active low, read control input. When
HCS# is low, HRD# low allows the host to read status information
or data from a selected MCU register.
Host Bus Interrupt. HINT output is set high when the receiver
error flag, received data available, transmitter holding register
empty, or modem status interrupt is asserted. HINT is reset low
upon the appropriate interrupt service or master reset operation.
Host Bus Address Lines 0-2. During a host read or write
operation with HCS# low, HA0-HA2 select an internal MCU
16550A-compatible register.
Host Bus Data Lines 0-7. HD0-HD7 are three-state input/output
lines providing bidirectional communication between the host and
the MCU. Data, control words, and status information are
transferred over HD0-HD7.
Signal Name/Description
102247B