UPD77018A NEC, UPD77018A Datasheet - Page 13

• Manufacturer Part Number: UPD77018A
• Description: 16 bits/ Fixed-point Digital Signal Processor
• Manufacturer: NEC

Remark
HA1
HA0
HCS
HRD
HWR
HRE
HWE
HD7 - HD0
P3 - P0
• I/O port
• Host interface
Symbol
Symbol
The state of the pins added 3S becomes high impedance when the host does not access host interface.
82
81
78
79
80
66
67
70 - 77
62 - 65
Pin No.
Pin No.
I/O (3S)
I/O
I/O
I/O
O
O
I
I
I
I
I
Specifies register which HD7 to HD0 access
Specifies bits of registers which HD7 to HD0 access
Chip select input
Host read input
Host write input
Host read enable output
Host write enable output
8 bits host data bus
I/O port
1: Accesses HST:
0: Accesses HDT(in): Host transmit data register when
0: Accesses HDT(out): Host receive data register when
• 1: Accesses bits 15-8 of HST, HDT(in) or HDT(out)
• 0: Accesses bits 7-0 of HST, HDT(in) or HDT(out)
Host interface status register
when HA1 = 0
HWR = 0
HRD = 0
Function
Function
PD77018A, 77019
13