Pin description – Rainbow Electronics AT75C220 User Manual
Page 3

AT75C220
3
Pin Description
Table 1. AT75C220 Pin Description List
Block
Pin Name
Function
Type
Common Bus
A[21:0]
Address Bus
Output
D[15:0]
Data Bus
Input/Output
NREQ
Bus Request
Input
NGNT
Bus Grant
Output
Synchronous Dynamic
Memory Controller
DCLK
SDRAM Clock
Output
DQM[1:0]
SDRAM Byte Masks
Output
CS0
SDRAM Chip Select 0
Output
CS1
SDRAM Chip Select 1
Output
RAS
Row Address Strobes
Output
CAS
Column Address Strobes
Output
WE
SDRAM Write Enable
Output
Static Memory Controller
NCE0, NCE3
Chip Selects
Output
NWE[1:0]
Byte Select/Write Enable
Output
NSOE
Output Enable
Output
NWR
Memory Block Write Enable
Output
NWAIT
Enable Wait States
Input
I/O Port A
PA[12:0]
General-purpose I/O lines. Multiplexed with
peripheral I/Os.
Input/Output
PA[19]
General-purpose I/O line. Multiplexed with
peripheral I/Os.
Input/Output
I/O Port B
PB[9:0]
General-purpose I/O lines. Multiplexed with
peripheral I/Os.
Input/Output
DSP Subsystem
OAKAIN[1:0]
OakDSPCore User Input
Input
OAKAOUT[1:0]
OakDSPCore User Output
Output
Timer/Counter 0
TCLK0
Timer 0 External Clock
Input
TIOA0
Timer 0 Signal A
Input/Output
TIOB0
Timer 0 Signal B
Input/Output
Timer/Counter 1
TCLK1
Timer 1 External Clock
Input
TIOA1
Timer 1 Signal A
Input/Output
TIOB1
Timer 1 Signal B
Input/Output
Watchdog
NWDOVF
Watchdog Overflow
Output