atf16v8c ATMEL Corporation, atf16v8c Datasheet - Page 8

• Manufacturer Part Number: atf16v8c
• Description: High- Performance Ee Pld
• Manufacturer: ATMEL Corporation

Macrocell Configuration
Software compilers support the three different OMC modes
as different device types. These device types are listed in
the table below. Most compilers have the ability to automat-
ically select the device type, generally based on the
register usage and output enable (OE) usage. Register
usage on the device forces the software to choose the reg-
istered mode. All combinatorial outputs with OE controlled
by the product term will force the software to choose the
complex mode. The software will choose the simple mode
only when all outputs are dedicated combinatorial without
OE control. The different device types listed in the table
can be used to override the automatic device selection by
the software. For further details, refer to the compiler soft-
ware manuals.
When using compiler software to configure the device, the
user must pay special attention to the following restrictions
in each mode.
In registered mode pin 1 and pin 11 are permanently con-
figured as clock and output enable, respectively. These
pins cannot be configured as dedicated inputs in the regis-
tered mode.
In complex mode pin 1 and pin 11 become dedicated
inputs and use the feedback paths of pin 19 and pin 12
respectively. Because of this feedback path usage, pin 19
and pin 12 do not have the feedback option in this mode.
In simple mode all feedback paths of the output pins are
routed via the adjacent pins. In doing so, the two inner most
pins (pins 15 and 16) will not have the feedback option as
these pins are always configured as dedicated combinato-
rial output.
ATF16V8C Registered Mode
PAL Device Emulation/PAL Replacement
The registered mode is used if one or more registers are
required. Each macrocell can be configured as either a reg-
istered or combinatorial output or I/O, or as an input. For a
registered output or I/O, the output is enabled by the OE
pin, and the register is clocked by the CLK pin. Eight
product terms are allocated to the sum term. For a combi-
natorial output or I/O, the output enable is controlled by a
product term, and seven product terms are allocated to the
sum term. When the macrocell is configured as an input,
the output enable is permanently disabled.
Any register usage will make the compiler select this mode.
The following registered devices can be emulated using
this mode:
16R8
16R6
16R4
8
16RP8
16RP6
16RP4
ATF16V8C
Registered Configuration for
Registered Mode
Notes:
Combinatorial Configuration for
Registered Mode
Notes:
1. Pin 1 controls common CLK for the registered
2. The development software configures all the archi-
1. Pin 1 and Pin 11 are permanently configured as CLK
2. The development software configures all the archi-
outputs.
Pin 11 controls common OE for the registered
outputs.
Pin 1 and Pin 11 are permanently configured as
CLK and OE.
tecture control bits and checks for proper pin usage
automatically.
and OE.
tecture control bits and checks for proper pin usage
automatically.
(1)(2)
(1)(2)