diff --git a/doc/classic_cli_manpage.rst b/doc/classic_cli_manpage.rst
index e2ce68472..c8aa61f09 100644
--- a/doc/classic_cli_manpage.rst
+++ b/doc/classic_cli_manpage.rst
@@ -616,6 +616,18 @@ Example::
         syntax where ``state`` is ``yes`` or ``no`` (default value). ``yes`` means active state of the pin implies that chip is
         write-protected (on real hardware the pin is usually negated, but not here).
 
+**Frequency**
+	Frequency can be specified in ``Hz`` (default), ``KHz``, or ``MHz`` (not case sensitive).
+	If ``freq`` parameter is passed in from command line, commands will delay for certain time before returning,
+	so that to emulate the requested frequency.
+
+	Valid range is [1Hz, 8000Mhz] and there is no delay by default.
+
+	The delay of an SPI command is proportional to the number of bits send over SPI bus in both directions
+	and is calculated based on the assumption that we transfer at 1 bit/Hz::
+
+		flashrom -p dummy:emulate=W25Q128FV,freq=64mhz
+
 
 nic3com, nicrealtek, nicnatsemi, nicintel, nicintel_eeprom, nicintel_spi, gfxnvidia, ogp_spi, drkaiser, satasii, satamv, atahpt, atavia, atapromise, it8212 programmers
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/dummyflasher.c b/dummyflasher.c
index cf4ca03b9..ef49f48f9 100644
--- a/dummyflasher.c
+++ b/dummyflasher.c
@@ -55,7 +55,7 @@ struct emu_data {
 	uint8_t emu_status_len;	/* number of emulated status registers */
 	/* If "freq" parameter is passed in from command line, commands will delay
 	 * for this period before returning. */
-	unsigned long int delay_us;
+	unsigned long long delay_ns;
 	unsigned int emu_max_byteprogram_size;
 	unsigned int emu_max_aai_size;
 	unsigned int emu_jedec_se_size;
@@ -901,7 +901,7 @@ static int dummy_spi_send_command(const struct flashctx *flash, unsigned int wri
 		msg_pspew(" 0x%02x", readarr[i]);
 	msg_pspew("\n");
 
-	default_delay((writecnt + readcnt) * emu_data->delay_us);
+	default_delay(((writecnt + readcnt) * emu_data->delay_ns) / 1000);
 	return 0;
 }
 
@@ -1128,7 +1128,7 @@ static int init_data(const struct programmer_cfg *cfg,
 	/* frequency to emulate in Hz (default), KHz, or MHz */
 	tmp = extract_programmer_param_str(cfg, "freq");
 	if (tmp) {
-		unsigned long int freq;
+		unsigned long long freq;
 		char *units = tmp;
 		char *end = tmp + strlen(tmp);
 
@@ -1166,13 +1166,13 @@ static int init_data(const struct programmer_cfg *cfg,
 			}
 		}
 
-		if (freq == 0) {
-			msg_perr("%s: invalid value 0 for freq parameter\n", __func__);
+		if (freq == 0 || freq > 8000000000) {
+			msg_perr("%s: invalid value %llu for freq parameter\n", __func__, freq);
 			free(tmp);
 			return 1;
 		}
 		/* Assume we only work with bytes and transfer at 1 bit/Hz */
-		data->delay_us = (1000000 * 8) / freq;
+		data->delay_ns = (1000000000ull * 8) / freq;
 	}
 	free(tmp);
 
@@ -1402,7 +1402,7 @@ static int dummy_init(const struct programmer_cfg *cfg)
 		return 1;
 	}
 	data->emu_chip = EMULATE_NONE;
-	data->delay_us = 0;
+	data->delay_ns = 0;
 	data->spi_write_256_chunksize = 256;
 
 	msg_pspew("%s\n", __func__);
diff --git a/tests/dummyflasher.c b/tests/dummyflasher.c
index 052938bec..9878bef70 100644
--- a/tests/dummyflasher.c
+++ b/tests/dummyflasher.c
@@ -141,6 +141,25 @@ void dummy_all_buses_test_success(void **state)
 	run_basic_lifecycle(state, &dummy_io, &programmer_dummy, "bus=parallel+lpc+spi");
 }
 
+void dummy_freq_param_init(void **state)
+{
+	struct io_mock_fallback_open_state dummy_fallback_open_state = {
+		.noc = 0,
+		.paths = { NULL },
+	};
+	const struct io_mock dummy_io = {
+		.fallback_open_state = &dummy_fallback_open_state,
+	};
+
+	run_basic_lifecycle(state, &dummy_io, &programmer_dummy, "bus=spi,freq=12Hz");
+	run_basic_lifecycle(state, &dummy_io, &programmer_dummy, "bus=spi,freq=123KHz");
+	run_basic_lifecycle(state, &dummy_io, &programmer_dummy, "bus=spi,freq=345MHz");
+	run_basic_lifecycle(state, &dummy_io, &programmer_dummy, "bus=spi,freq=8000MHz");
+	/* Valid values for freq param are within the range [1Hz, 8000Mhz] */
+	run_init_error_path(state, &dummy_io, &programmer_dummy, "bus=spi,freq=0Hz", 0x1);
+	run_init_error_path(state, &dummy_io, &programmer_dummy, "bus=spi,freq=8001Mhz", 0x1);
+}
+
 #else
 	SKIP_TEST(dummy_basic_lifecycle_test_success)
 	SKIP_TEST(dummy_probe_lifecycle_test_success)
@@ -150,4 +169,5 @@ void dummy_all_buses_test_success(void **state)
 	SKIP_TEST(dummy_init_success_unhandled_param_test_success)
 	SKIP_TEST(dummy_null_prog_param_test_success)
 	SKIP_TEST(dummy_all_buses_test_success)
+	SKIP_TEST(dummy_freq_param_init)
 #endif /* CONFIG_DUMMY */
diff --git a/tests/tests.c b/tests/tests.c
index 78f1b4772..8a9dc6b4f 100644
--- a/tests/tests.c
+++ b/tests/tests.c
@@ -461,6 +461,7 @@ int main(int argc, char *argv[])
 		cmocka_unit_test(dummy_init_success_unhandled_param_test_success),
 		cmocka_unit_test(dummy_null_prog_param_test_success),
 		cmocka_unit_test(dummy_all_buses_test_success),
+		cmocka_unit_test(dummy_freq_param_init),
 		cmocka_unit_test(nicrealtek_basic_lifecycle_test_success),
 		cmocka_unit_test(raiden_debug_basic_lifecycle_test_success),
 		cmocka_unit_test(raiden_debug_targetAP_basic_lifecycle_test_success),
diff --git a/tests/tests.h b/tests/tests.h
index 3536d1d12..100bda1bc 100644
--- a/tests/tests.h
+++ b/tests/tests.h
@@ -53,6 +53,7 @@ void dummy_init_success_invalid_param_test_success(void **state);
 void dummy_init_success_unhandled_param_test_success(void **state);
 void dummy_null_prog_param_test_success(void **state);
 void dummy_all_buses_test_success(void **state);
+void dummy_freq_param_init(void **state);
 void nicrealtek_basic_lifecycle_test_success(void **state);
 void raiden_debug_basic_lifecycle_test_success(void **state);
 void raiden_debug_targetAP_basic_lifecycle_test_success(void **state);